Does your worm bin have uninvited pests or does it simply stink?
Are your worms looking deformed?
Are they trying to escape?
You first need to understand that when trying to maintain an environment worms will love, other critters will find that environment to be lovely as well.
Most of them are not actually pests, but desirable decomposers that work hand-in-hand with your worms. (Let’s pretend worms have hands for a second!)
This article will cover just about everything that you may observe in a worm bin, from springtails to mold to isopods. Learn how to identify common worm bin residents, whether they are good and bad, and what to do if you should find yourself with an infestation.
We’ll also chat about other worm bin problems like bad smells, worms escaping, protein poisoning, mold, and other issues you probably don’t want!
Common Worm Bin Inhabitants
Anyone who has maintained a worm bin quickly finds that they are dwellings for more than just worms. It’s hard to maintain a moist, warm, rich environment and not find some uninvited guests.
But most other life forms in the bin help the worms and microbes to decompose food scraps and organic matter.
Like worms, most worm bin critters live in the leaf litter and shallow layers of soil in forests and fields. Their role in nature is to speed decomposition by shredding bits of organic matter into smaller pieces. Shredding and fragmenting increases the surface area, allowing more bacteria and fungi to move in and break things down even farther, bringing about nutrient cycling to aid plant health.
There are only a few that will cause damage to our precious composting worms.
The following are common worm bin inhabitants that you may find, other than composting worms. Most of them are simply “co-composters” rather than being pests and problems. They usually sneak into your bin as eggs hidden in some type of organic material from the yard or kitchen.
Good Worm Bin Inhabitants: The Little Friends & Happy Accidents
Channeling Al Pacino from Scarface, we should “say hello to our little friends!”
If violent 80s drug movies aren’t your thing, then do your best Bob Ross imitation and refer to these worm bin critters as “happy accidents.”
See below for a some worm bin inhabitants that help – not harm – the decomposition in your bin.
Springtails, aka Collembola
These creatures are small, wingless hexapods which range in size from a sixteenth to a quarter of an inch long.
They can appear as whitish jumpy creatures but can also be colored grey, yellow, orange, red, brown, or even purple.
Commonly found in moist grassy or wooded areas, they tend to hide under bark and rocks, or among leaf litter. Their diet mainly consists of bacteria, fungi, and decaying vegetation.
Springtails, or collembola, have an interesting tube protruding from their abdomen called a collophone. The word Collembola means “glue peg”, derived from the old belief that this tube was a way of holding the springtail up while standing.
This tubelike structure is likely used for moisture intake and excretion, as opposed to keeping the springtail upright.
Collembola don’t mate in the typical fashion of direct contact. Rather, the male drops a packet of sperm known as a spermatophore near the female. The female then picks up the spermatophore with her genital opening. Some males will surround a female with a fence of stalked spermatophores, virtually guaranteeing that their genetics will be carried on.
Some winter active species of springtail have a type of antifreeze in their blood to keep their cells from freezing in subzero temperatures, similar to the antifreeze in our automobiles. You may have seen dark patches on top of snow that were actually a bunch of springtails on the surface.
Springtails are little cause for concern in a worm bin and it is unlikely that their populations will get out of control. Their presence contributes to breaking organic matter down into soil and hummus in a worm bin.
Isopods are known by several names: roly-poly, pill bug, sowbug, and woodlice.
These tiny animals are all part of the class Crustacea which includes crayfish, crabs, shrimp, and lobsters.
The majority of the world’s 4000 species of isopods are actually ocean-dwelling beings. A small segment, generally known as woodlice, inhabit terrestrial homes. They are usually blackish, brownish, or greyish in color and 1/4 to 5/8 of an inch long.
Isopods rely on moisture in order to breathe, so they are found in dark, damp environments. They feed on fungi, algae, and rotting wood, along with decaying plant and animal matter. Like other worm bin tenants, isopods are most active at night, preferring to hide during the day.
Similar to their shellfish kin, isopods have a series of broadly arched, overlapping segments that make up a coating of armor on their backs. Each segment contains a pair of platelike legs, called pleopods, that serve as respiratory instruments. These pleopods must remain moist in order for isopods to breathe and survive.
The last abdominal segment on the woodlice has a pair of leglike appendages known as uropods which take up moisture and dispose of waste. In females, there is a section of thorax with overlapping plates that forms a marsupium, or brood pouch, to carry around their young.
The common pillbug can roll itself up into a ball to form a nearly impenetrable defense to predators, like an armadillo does. Sowbugs, which are a similar isopod, are not able to roll themselves into such a ball.
Isopods should not cause any harm in a worm bin. Like springtails, they will help to break down food scraps and organic matter to create soil.
If you absolutely must get rid of them, either remove them manually or use food grade diatomaceous earth to kill these hard-shelled isopods without harming your worms.
Potworms aka Enchytraeids
Potworms cause either alarm or giddiness for new worm bin owners.
These small, white, segmented worms are typically a little more than a quarter inch long and will appear by the hundreds or thousands.
They are a relative of earthworms so you can forgive new worm bin owners for thinking their worms are reproducing like crazy.
But they lack hemoglobin-based blood, which causes their whitish coloring. This is the biggest giveaway that you’ve got a potworms instead of baby composting worms.
Potworms are fellow composters, further fragmenting organic waste. They can appear to be competition for the worms we are trying to farm, but they generally aren’t an issue.
While potworms themselves cause no problems for worms, their presence indicates wet, acidic conditions.
A common technique is to place a piece of bread in the bin and pour a small amount of milk on it. The acid-loving potworms will congregate on the bread which can be removed and thrown away.
Moving forward, add more bedding to your additions of food waste and consider a sprinkling of agricultural lime on the surface of your vermicompost to raise the pH in the bin.
Earwigs, aka Dermaptera
Earwigs are one of the scarier looking creatures that inhabit a worm bin.
They have long, flattened bodies with pincers, called cerci, at the abdomen tip. Earwigs are brown or blackish in color and range in size from one quarter to one and a half inches long. The cerci on males is forcep-shaped, resembling a sideways C. Females have straighter, more U-shaped cerci.
Earwigs are both predators and scavengers feeding on mites, spiders, and microbes along with living and dead insects or plants. They prefer to be active at night like other worm bin lodgers and prefer moist, dark places to reside. There are around 1800 species worldwide, about 22 of which live in the temperate climates covering North America.
The name Earwig comes from an old European belief that these insects purposely crawled into the ears of sleeping individuals. Hopefully none of you readers keep worm bins anywhere near your bedrooms. Seriously though, earwigs are another worm bin inhabitant that you shouldn’t give much concern.
Fun fact. In some species of earwigs, the females will care for their eggs by licking them and turning them over. This action keeps them moist and free from molds.
Earwigs are not known to eat live worms and their presence alone should not be a cause for concern in a worm bin.
Fruit Flies and Fungus Gnats
Fruit flies are tiny and generally black, but may have wings with colorful patterning. Fungus gnats are one eighth to one quarter of an inch long, brown or black in color, and resemble a mosquito with their long antennae and pointed abdomen.
Both of these flies are really more of a nuisance than a problem.
All flies thrive in wet conditions. A moist worm bin is the perfect place to make a home.
The best way to keep flies under control will be to keep newly-added foods covered or buried. A great solution in the Urban Worm Bag is to open the top a small amount, insert a vacuum hose, and hoover those little nuisances up.
Do you want to prevent or eliminate fruit flies? Check this out this article on how to keep these little buggers at bay!
You’ll find more than 7000 species of millipedes, mostly in tropical regions. 1400 exist in North America.
Millipede is Latin for “1000” and “foot”, but the average millipede actually has fewer than 100 feet.
Millipedes have a rounded body and are normally dark black, brown, or greenish in color. Many are pale or pinkish, some even have rings of scarlet or bright yellow. A genus found in California named Motyxia is bioluminescent and glows in the dark. Millepedes have two pairs of legs on the majority of their segments. Each segment is actually a diplosegment, which is two segments fused together.
Most millipedes are detritivores, consuming rotting vegetation as well as fungi. Some ingest soil in the same manner as earthworms, mainly getting their nutrients from microbes. To keep away predators, some millipedes coil themselves up, others roll themselves into a ball, and a few release a smelly, yellowish liquid as a chemical defense.
It is rare to find high numbers of them in any worm bin. Any that are found have likely hitched a ride into the bin on manure, leaf mold, or pre-composted material. You can leave them in a worm bin to assist in the breakdown of organic matter or pick them out of the bin.
Millipedes are vegetarians and, therefore, harmless to worms.
Mold is a fungus that usually grows as white, hair-like structures called hyphae. It may also appear as a white, green, or orange powdery substance typically found growing on food scraps. It is the only non-animal that is visible to the naked eye in a worm bin.
Anyone who has left bread or fruit out too long is surely familiar with the appearance of mold.
There is nothing to be concerned about if you find mold in a worm bin. The fungus is working to decompose food scraps and organic waste.
But if you always find lots of mold in the bin, you’ve likely added too much food waste and not enough “brown” bedding material.
Dog Vomit Slime Mold
With a “nerd” name of Fuligo septica, Dog Vomit Slime Mold is a visually repulsive growth of a scrambled egg-colored protist, most closely related to amoebae.
It appears in warm moist conditions, rich in organic matter and it especially likes complex, woody waste like mulch.
Despite being one of the grossest-looking worm bin inhabitants, Dog Vomit Slime Mold, like most critters in the worm bin, is working alongside your worms to fragment organic waste and turn nutrients into forms that plants can eat.
Fuligo septica is more of an indication that you’re doing something right, not wrong.
Bad Worm Inhabitants: Critters To Be Cautious About
Centipedes often get confused with millipedes, although there are a few major differences. These guys have only one pair of legs per body segment along with flattened body shapes. The last set of legs extend far beyond the body, and are used for defense purposes or to subdue prey.
There are roughly 3150 species around the globe. Most are brownish-yellow and have two major body segments, the head and the segmented trunk. While centipede is Latin for “100” and “foot”, centipedes have anywhere from 15 to more than 50 sets of legs.
They are the only animal in the world with legs that are modified into fangs. These fangs are used for injecting poison into their prey to subdue and kill them. The legs, called prehensors, are located under the head and have glands that release venom into ducts that lead into their claws.
Centipedes are one of only a few animals that will feed on worms, and should be removed or killed when found in a bin.
You can pinch them to kill them, and then leave them to decompose in the bin.
Black Soldier Flies & Larvae
Black soldier flies enjoy moist, shaded places to call home, especially in hotter climates.
The are easy to distinguish from other species. They are one half to three quarters of an inch long, pitch black in color, and have a flat, wasplike shape. As the flies themselves do not have mouths, they will die within 1-2 days of emerging from the pupal stage
Their larvae look like leathery beige or blackish flattened tubes. Adults appear sluggish and inactive, resting on decaying organic waste that they feed upon.
Black soldier fly larva, often referred to as BSFL are a cause for concern in a worm bin
They consume organic waste 75 times faster than composting worms and will outcompete your worms for food.
BSFL are also reported to increase heat in a worm bin.
Getting Rid of Black Soldier Fly Larvae in a Worm Bin
If you can catch an infestation of BSFL early, then the best bet is to remove the larvae manually and inspect the bin daily until you’re sure you’ve gotten them all.
This is tedious, but it’s about the only way.
Any material that is infested with black soldiers flies and larvae can be placed outside, particularly on a compost pile, to break down while being exposed to sunlight and air.
Chickens, of course, will love the protein-rich BSFL, but they will also love the protein-rich worms too. So setting chickens loose on the worm bin is probably out of the question.
The only other option we’re aware of is starting the bin over again. Using some of your existing, non-infested vermicompost will help jumpstart your new worm bin.
Most mites are scavengers of plant detritus along with eating mycelium and microbes. Other species are predatory, consuming springtails, nematodes, small annelids, insect eggs, and other mites.
Mites are the most abundant microarthropod, but they aren’t just found in soils. Almost every type of beetle, snake, bird, plant, human, and most anything else have between one and four associated species of mites that live on them. They can also be found in caves, trees, even water.
Many mites hitch rides by attaching themselves to flying insects, in order to spread their populations out over greater areas. Mites themselves act as taxicabs for even smaller microbes, allowing those microorganisms to migrate to new places.
Several species of mites can be observed in a worm bin. If a bin is not managed properly, acidity can increase, making the ideal conditions for mites to thrive.
Check the pH of your bin regularly if you find yourself concerned. Agricultural lime can be added to make the material more alkaline if the pH drops to less than around 6.8.
In general, brown and white mites do not prey on healthy worms, but may consume worms that are hurt or deceased. If their populations become out of control, they can consume much of the worm bin material.
This robs the worms of their critical nutrients.
Red mites are the most problematic of any in the worm bin. They can keep worms from feeding, virtually starving them. They also parasitize worms, sucking out both their blood and bodily fluids. Red mites are also capable of harming worm cocoons by draining them of their fluids.
Red mites rarely become a serious issue. The three main conditions that usually lead to a mite infestation are excessive moisture and overfeeding.
Methods For Ridding a Worm Bin of Mites
You can get rid of mites by simply making the conditions in a bin unfavorable to them.
Leave the cover off of a bin for two to three days to allow the material within to dry up a bit.
You can help this by adding small bits of shredded corrugated cardboard or newspaper to absorb the excess moisture. Adding a light above the bin while the cover is off may help to drive the mites away as well.
Some people have had success using moistened burlap or newspaper. Wet the burlap or newspaper and then place on top of the bin. Mites should accumulate on the surfaces. Remove the newspaper or burlap after a large amount of the mites have amassed on the material.
Lastly, a piece of bread or slice of melon placed on top the organic matter in the bin can attract mites. After the mites start to congregate on the slice of bread or melon, remove it and place in an outdoor compost bin or bury it in the soil.
Learn More About Mites in the Worm Bin
Why are mites in your worm bin? And how do you get rid of them? Check out this helpful article!
Ants are relatives of bees and wasps, belonging to the order hymenoptera.
There are about 9500 species of ants.
Most ants observed around worm bins are one sixteenth to one quarter inch long, but some ant species can get as long as one inch. They are brown, black, or reddish in color, and form elaborate social structures made up of a caste system.
Colonies of ants make homes in underground tunnels or in abandoned termite galleries in dead wood. The majority of ants are predators or scavengers feeding on other insects and spiders.
Ants can be a problem in worm bins, especially in hotter climates, as some species feed on smaller worms as well as cocoons. If you notice a line of ants marching into your bin there are a few solutions to keep them at bay.
How to Prevent Ants from Entering Your Worm Bin
- sprinkle a path of diatomaceous earth around the worm bin
- apply a one inch strip of petroleum jelly around the legs or sides of a worm bin
- place the legs of a worm bin in coffee cans and filling the cans with some mineral oil to create a physical barrier for the ants.
- as a last resort, use chemical sprays or baits on the exterior of your worm bin
Predatory planarians may feed on earthworms, but it is rare to find them in a worm bin.
Planarians are flatworms that prefer dark, moist places full of organic matter where they may find food. They grow up to several inches long, with thousands of cilia on their underside which move them along in a gliding motion.
Also known as “hammerhead worms”, their genus name is Bipalium, from Latin bi meaning “two”, and pala meaning “shovel” because of their pickaxe shape.
Planarians prey on worms by moving in on them, grabbing hold, and attaching their pharynx to the worm. Enzymes are released by the planarian, liquifying the worm, and allowing the planarian to suck it up through its pharynx. . . Mmmmm worm shake anyone?
Non-Critter Worm Bin Issues
The problems below have origins NOT caused by the invasion of other life forms. They are typically man-made issues arising from overfeeding and not protecting your worm bin from the elements.
Cold Temperatures in the Worm Bin
Wintertime temperatures are certainly a challenge for a worm bin owner. As the temperatures approach 55°F, you can expect organic waste consumption and reproduction to begin slowing. Activity, though not worm life itself, will slow in the 45° range and you can expect worms – thought not necessarily the cocoons – to perish in freezing temperatures.
Ways to fight low worm bin temperatures:
- keep your worm bin indoors whenever possible – duh, right?
- step up your feedings to boost temperatures
- insulate the worm bin and protect from direct exposure to the weather
- use a seed starting mat to keep temperatures warmer in the Urban Worm Bag and other bins!
Want to learn how to keep your worm bin humming – or at least surviving – through the winter?
Would You Rather Watch a Video?
Hot Temperatures in the Worm Bin
Unlike cold temperatures where we can blame Mother Nature, hot temperatures in a worm bin can be caused by both nature and our own mistakes.
And unlike the slow death brought on by low temperatures, high temperatures can quickly doom your worm bin.
Of course, high air temperatures surrounding a worm bin will affect the temperatures inside the vermicompost.
But dumping large amounts of nitrogen-rich green waste into a worm bin can also create rotting pockets of heat.
Vermicompost temperatures exceeding 95 degrees will result in a quick death for worms that cannot find a way to escape.
Learn how to overcome hot temperatures to keep your worms alive during extreme heat!
Excess Moisture & Leachate
Worms love moisture. And children love ice cream.
But let’s not misinterpret this affinity as encouragement to keep our children filled up with ice cream or our worm bins chock full of moisture.
Most commercial home use worm bins – the Urban Worm Bag not being one of them! – have a tap-like mechanism to release excess moisture called leachate into some sort of a catch. Unfortunately, most users see this as an inducement to create vermicompost wet enough to produce this liquid.
Most commercial worm bins also assume the movement of worms upwards, through perforated trays in stackable-tray worm bins or to the surface of the vermicompost in single-compartment bins like the Urban Worm Bag or Hungry Bin.
However, if your worm bin is wet enough to produce leachate at the bottom, your worms will stubbornly wallow in it, defeating the point of these worm bins in the first place.
Wet vermicompost is difficult to harvest and can create nasty odors as you’ll see below.
Foul Odors & Anaerobic Conditions
When you’ve got excess moisture, anaerobic conditions aren’t far behind.
If your primary feedstock is fruit and vegetable waste, you are (maybe unknowingly) dumping lots of water into your bin as well.
As the waste – which is around 85+% water content – breaks down, the cell walls release water in your vermicompost. Without enough bedding to absorb the moisture, the water displaces the oxygen in the little pockets of air in your vermicompost called pore space.
Your vast microbe population will rapidly consume the available oxygen in that leachate and it will quickly turn anaerobic. And when things begin decaying in the absence of oxygen, they start smelling nasty.
When your worms get protein poisoning, that’s your most blatant warning that you’ve overdone it on the feeding.
Protein poisoning, aka “string of pearls,” is a nasty non-contagious affliction where acids inside the worm’s’ gut begin fermenting, literally blowing up the worm from the inside out.
Worms have a calciferous gland that, under normal circumstances, helps neutralize acidic organic waste. When worms are fed a diet of food waste without a sufficient helping of worm bedding, the pH can drop so low that the worm cannot maintain a neutral pH.
Protein poisoning cannot be passed from worm to worm so you don’t need to remove the doomed worms from the rest of your bin. But you do need to do the following:
- stop feeding any more organic waste, specifically food waste
- add a dusting of agricultural lime or calcium carbonate. Pulverized egg shells will do the trick if you have enough of them
- add a 3-inch layer of dry bedding to your worm bin and mix it into the top few inches
Moving forward, reduce food waste additions and use grain-based worm chow products only as a supplement. Chow should never be the primary food source in a worm bin.
Worm Escaping the Bin
We should distinguish between normal worm behavior and an indication that things have gone sideways in your worm bin.
A few dozen worms exploring the condensation on the walls of your worm bin is no cause for concern.
But when it seems like your entire worm population is making a run for it, now you’ve got a problem. Worms will typically try to escape a hot worm bin or when you’ve created noxious conditions for them.
Learn More About Worms On the Walls of Your Bin
Wondering why worms are seemingly trying to escape? learn whether or not you’ve got a problem or if this is normal worm behavior.
Preventing Infestations and Foul Odors In a Worm Bin
Add Food *and* Bedding
The most common mistake that people make after starting a worm bin is adding only green, nitrogenous material without brown, carbonaceous material.
Food scraps are 90% moisture on average and they tend to decompose very quickly.
That’s a lot of water! And a lot of potential rotting!
You want to keep the water content in your worm bin between 50-70%.
For reference, when squeezing a handful of vermicompost, if you get one drop of liquid, that is just shy of 70%.
50% is when the material is tacky and will stick to itself when compressed.
In order to balance it out, the bin needs a copious amount of browns, or what most people consider bedding material.
Decomposing leaves, or shredded newspaper or cardboard make an excellent addition of higher carbon matter. Pitt Moss makes an excellent product made from recycled newspapers, although most people have plenty of junk mail, newspaper, and brown grocery bags to reuse in a worm bin.
We recommend a ratio of 2:1, bedding to food waste, by volume. Understand that bedding is also a food, albeit a food that breaks down more slowly.
You will alleviate 90% of worm bin problems by adding bedding with your food waste.
Learn More About Worm Bin Bedding
Wondering what to use for worm bedding? Read this handy list of common worm bin bedding choices!
Cover Food Waste to Prevent Odors and Critters
It is best to always cover any added food scraps with some type of carbonaceous material such as shredded newspaper.
At the very least, bury newly added food scraps a few inches deep into the existing contents. This will help to keep things like flies and mites at a minimum.
Keeping a cover over the organic matter in the bin, such as the Urban Worm Blanket, will also work to keep insect pests from laying eggs on the top of the bin material. Thus reducing future populations.
Go Easy On The Food
We’ll say it again. Overfeeding can cause more issues than insect infestations.
Adding too much food without allowing the worms time to process it all can lead to fermentation, lowering the pH of the material, likely causing anaerobic conditions, and possibly causing protein poisoning. Adjust the amount or frequency of feeding in order that the worms are able to chew through what has been added to the bin.
One of the main symptoms that worm bin owners notice when dealing with a lower pH, and anaerobic conditions is worms escaping out of the bin. You will normally notice small groups of worms here and there who are congregating on the walls of the bin. This is natural.
When the worms truly escape they are seeking shelter far away from the bin and you will definitely notice a problem.
Also, avoid adding food scraps with high salt content. Salts take up moisture and can be an issue for worms who need to remain moist in order to breath.
Understand When It’s Time to Feed Again & How Much
When all of the newer material has been worked through by worms, you will notice the “pool table effect” on the top.
Instead of a rough surface full of chunks, the top will look smooth and flat, like the felt on a pool table.
This pool table effect is your green light to begin feeding again.
Add new food for the worms in layers around a half inch thick. Understand that this is the thickness of the food waste only! You’ll want to add twice that volume in bedding.
Although some folks like the lasagna method of feeding where you have distinct layers of food waste and bedding, we like the idea of mixing food waste and bedding together before feeding.
If it appears that the worms are processing the material quickly, you can increase the feedings. Of course, if you see or smell anything undesirable, reducing the feedings is a good move.
Learn More About What to Feed Worms
Use this easy-to-read article to guide you on what to feed your worms!
Be Patient, Add Bedding, and Worm On!
Caring for a worm bin can be a fun way of reducing waste, recycling food scraps, and making a natural fertilizer for your garden. In the same way that a garden is home to more than just plants, a worm bin is an ideal habitat for worms. But insects and other organisms as well will find your bin attractive too!
That’s just nature.
Keep bedding levels high, go easy on the feedings, and be patient, especially with a new worm bin!
Do this and you’ll keep a happy, healthy population of worms and a limited number of pests!