How to Solve the Most Common Worm Farm Problems

Quite a few worm farm problems happening here! Overfeeding, too many carbs, no bedding, rotting food, some friendly pests and probably a foul smell...
Quite a few worm farm problems happening here! Overfeeding, too many carbs, no bedding, rotting food, some friendly pests and probably a foul smell…

Many worm farm problems that occur are avoidable through proper worm farm maintenance. This includes:

  • Not overfeeding your worms.
  • Add the right food scraps. Do not add meat, dairy, greasy or oily food, pet feces, or too much acidic food.
  • Keeping the carbon-to-nitrogen ratio at least 1:1 or higher – when in doubt, add more paper.
  • Regulating the worm bin temperature between 59° – 86° Fahrenheit or 15° – 30° Celsius. Always remember that worms like the same temperatures as humans.
  • Make sure your worms are always comfortable. Provide sufficient worm bin bedding and ensure the moisture level of worm bin is moist (but not too moist!!!).

When I first started my worm farming odyssey, I learned the hard way through a series of trial and error. I hope you can forgive me. As a male, I’m not hard-wired to read the manual until something goes wrong.

Here’s a list of the most common worm farm problems and possible solutions to resolve them. All of which I wish I knew when I first started worm farming.

How to Start a Worm Farm

You might want to check out this “ultimate” guide on how to start a worm farm.

Worm Farm Problem #1 – Too Hot

Worms will try to migrate to cooler spots in the worm farm such as the base when it starts to get too hot.
Worms will try to migrate to cooler spots in the worm farm such as the base when it starts to get too hot.

This worm farm problem is a real challenge in the Summer heat.

When your worm bin starts to get too hot, your worms will migrate to cooler areas (or trays). They will also eat less food and slow down reproduction.

Worms will likely suffer and die if temperatures exceed 95° Fahrenheit or 35° Celsius.


On hot days freeze a water bottle, wrap it in some newspaper and bury it deep in your worm farm.
On hot days freeze a water bottle, wrap it in some newspaper and bury it deep in your worm farm.
  • Place your worm bin so that it is not in direct sunlight (e.g. under a tree). Limit exposure to the sun when its impact is most strong (morning or afternoon). Also try setting up some shade cloth for sun protection.
  • Cover the worm bin with light-colored materials such as second-hand carpet. You can also build a custom cover for your worm bin (e.g. a polystyrene box that you can place your worm bin in).
  • Move the worm bin to a cooler place such as indoors. Be mindful that many garages exceed 95° Fahrenheit or 35° Celsius.
  • Keep the bedding moist. Be careful not add too much water as this can boil them. Soggy bedding can heat up much more than dryer bedding. Use a watering can or spray bottle to keep the bedding wet.
  • Don’t put too much food scraps in the worm bin. Excess food will decompose and heat up the bin.
  • A low carbon to nitrogen ratio increases the temperature in the worm bin. Add some more carbon to offset the nitrogen (e.g. cardboard, shredded paper, eggs cartons etc…).
  • On hot days freeze a bottle of water, wrap it in some newspaper and bury it deep in your worm farm to create a cool zone. Replace the bottle as it defrosts. You can also try adding a large ice block on top. The worms will congregate upstairs to stay cool. The ice block should take several hours to melt completely.
  • Drape a damp cloth or hessian over worm farm so it acts as evaporate cooling.
  • Paint your worm farm a light color so it reflects more heat.
  • Apply lots of bedding respite (mix in some compost with worm castings). Extra bedding will act as an insulator against extreme temperatures and offer protection.

Find out how to regulate worm bin temperature.

Worm Farm Problem #2 – Too Cold

In extreme conditions, worms like humans will not survive the cold.
In extreme conditions, worms like humans will not survive the cold.

If your worms are too cold, they will crawl a lot and eventually mass together in a ball to keep warm. The worms will also eat less food and slow down reproduction.

If conditions get too cold, your worms may go into a bit of a survival mode, causing them to reproduce in a hurry. In extreme cold (i.e. 40° Fahrenheit or 4° Celsius), your worms will likely perish.


  • Adding in more nitrogen will increase the temperature. Feed your worms foods that are higher nitrogen, this will generate more heat as it breaks down. This means fewer fruits and more legumes and vegetables.
  • Insulate the worm bin, wrap it in wool, cardboard, fabric etc…, to trap the heat in. Be careful not to wrap too tight restricting ventilation.
  • Move the worm bin to a warmer place (e.g. near external exhaust vents of heating system)
  • Add a heat source such as a heat lamp or a spotlight
  • Add some pre-soaked newspaper on top of your worms bedding
  • Refrain from opening your worm bin lid as this will let the cold in
  • Bury your worm bin partially in the ground
  • Add dry leaves, straw or grass on top
  • Make your worm bin floorless to let your worms burrow deep into the ground to stay warm

Worm Farm Problem #3 – Too Wet

Too much moisture can drown your worms. The bedding in your worm bin should be as moist as a wrung-out sponge. If you can squeeze water out of a fistful of bedding, or if you see puddles, then your worm bin is too wet.

If your worm bin becomes too wet, it can become anaerobic (meaning no oxygen) with rotting food and produce a foul odour. Worms will naturally aerate the compost.

If your worms are becoming pale in color, or are skinny rather than nice and fat and healthy, your worm farm moisture levels are probably too high.


  • Add some fresh dry bedding material such as straw and paper. This will soak up some of the moisture.
  • Make sure you are not over-feeding the worms as this can cause excess moisture. Stop adding food for a bit so the bin can dry out a bit more.
  • Reduce food scraps that are high in water content (e.g. cucumber and lettuce are 96% water).
  • Stop watering for a while
  • Check the drainage of your worm bin to ensure there are no blockages

Worm Farm Problem #4 – Too Dry

Worms need moisture to breathe. If a worm bin is too dry, they will suffocate.
Worms need moisture to breathe. If a worm bin is too dry, they will suffocate.

All worms breathe through their skin. If a worm’s skin dries out, they will die.

If your worm farm isn’t producing any worm tea, then it’s a sign that the moisture level is going the other way. An ant infestation is usually a sign that your worm bin bedding is too dry.


  • Add some water using a spray bottle until you have the correct moisture level
  • Add more organic waste with a higher water content

Worm Farm Problem #5 – Too Acidic (Low pH Levels)

Another common problem is worm bin acidity. A good worm farm should smell earthy. If your worm bin smells rotten and vinegary, then it’s most likely that your worm bin is too acidic. Correct pH levels help worms to digest larger quantities of food waste. Worms are quite tolerant of acidic conditions.

pH, the potential of hydrogen, is a numeric scale between 0 and 14 used to specify acidity or alkalinity. 7 is neutral where lower values are more acid and higher values more alkaline. For example, lemon juice is at pH 2, pure water is neutral and seawater is at pH 8. A good pH level for a worm farm is between 6 and 7.

Some foods are more acidic than others (e.g. citrus fruits). Acidity is also produced through microbial fermentation. Excess amounts of acidic fruits, such as oranges, can contribute to a worm farm with low pH levels.

If your worms become deformed, discolored or dismembered, they may have protein poisoning (also known as sour crop or string-of-pearls). Protein poisoning is a direct result of overfeeding which creates a toxic environment.


  • Add pH neutral minerals such crushed eggshells, garden soil, dolomite, and crushed lime.
  • There are some worm farm conditioner products you can buy. Sprinkle a light even coating of powder across the top surface of your worm bin. This will help to neutralize and balance the pH levels.
  • Add some fresh bedding to offset the pH level
  • Get some clean air to your worms. Gently aerate the bedding by lifting and turning it.
  • If there is excess food waste, then it will decompose and create a toxic environment.
  • Remove any uneaten food which may be fermenting in the worm bin.

Worm Farm Problem #6  – Unwanted Pests

While some pests can become a big worm farm problem, many other inhabitants are harmless. Most pests pose no threat unless their population spirals too high.

The most effective prevention is to ensure your worm bin is well maintained. And make sure the worm bin lid is securely on to keep the pests out!


  • Potworms  – Large populations of these tiny white worms can be reduced by placing some bread oaked in milk in the bin, then you can discard the bread after a few hours. Hopefully some of potworms go with it 🙂
  • Springtails & mites – Try cutting back on water and feed. Add some calcium carbonate to raise the pH levels (reducing acidity)
  • Fruit flies in worm bin – Cover fruit with some bedding. Try custom traps to reduce the population. Wash produce before consumption to remove eggs. Try microwaving or freezing food waste before adding it to the worm bin (letting the food waste return to room temperature of course).
  • Slugs, snails, centipedes – Remove by hand.
  • Spider in worm bin – Spiders like dry conditions and prey on insects. Avoid overfeeding worms to reduce the number of insects attracted to rotting foods and keep the bin moist.
  • Ants – Ants are a sign that your worm bin is not moist enough. A good splash of water usually fixes it. Do not use insecticide. If your worm bin is on legs, place each leg in a dish of water to stop the ants getting in. Try sprinkling ground cinnamon wherever the ants are. You can also move the worm bin somewhere else.
  • Blowflies & house flies – Do not add any meat, greasy food waste, or pet feces as feed. A well maintained worm farm should not stink, which is what attracts flies.
  • Earwigs, beetles, millipedes, soldier flies, sow bugs & pill bugs – Do not worry about these – they are harmless.
  • Maggots or larvae – Eggs are laid on the surface of nitrogen rich material. Cover and bury nitrogen rich food waste. Add leaves, dry grass and shredded paper on top. Try putting a window screen over any holes in the bin.
  • Land planarian flat worms – Will attack your worms by the masses and reproduce quickly. Remove immediately and check your worm bin at least twice a day for others.

28 thoughts on “How to Solve the Most Common Worm Farm Problems

  1. Hi, all my worms got cooked on that 47 degree day. I’ve added the top tray to the compost bin. The bottom tray was almost ready – I was just waiting till the top tray got full. Can I just add more worms to the existing two trays? Or do I need to completely start again?

    1. Worms move around between the trays. For example, on hot days, they will look for cooler areas. They will also move to where the food source is. So it doesn’t really matter which tray you add your worms to. But I always add them to the “working” tray – the top tray. On extreme days, you should move your bin inside temporarily. If you have a lot of worms perish under extreme heat, take note that your dwindling worm population should recover ok. Worms are very resilient.

  2. My daughter gave me her worm farm as she was moving. I don’t think she has looked after it properly as the bottom tray from what I can gather should just have water, this one has what looks like wet castings it also has worms in it. What should I do?

    1. With a tray system, it is perfectly normal for castings to fall through to the bottom tray. You just need to clean it every few months to avoid any drainage blockages. Your worms may venture down below occasionally. That’s ok. Remember to drain any excess liquid as worms can drown. I keep my spigot (tap) open.

      1. How do the worms get back up. I found lots of casting and worms in the bottom try and spent ages trying to save them as I thought they would drown.

        1. A lot of commercial worm farms have a “ladder” or “slope” in the bottom tray so that the worms can climb back up. Some people add a layer of cardboard or mesh to stop the worms venturing down below. But I wouldn’t worry about the worms in the bottom tray. Just ensure the spigot is open to ensure any excess liquid drains and you should be right. The worms will gradually move up to the top trays to feed.

  3. Don’t sweat it! I don’t do any of the above. I feed too much, I add dog faeces, I add onion waste , I don’t cool the farm, I don’t need to warm it, I don’t ensure it’s too wet or too dry. Sometimes I get die offs but they always rebound. I’ve had the farm for nearly 20 years and it’s the simplest thing. Don’t overthink it! And don’t, whatever you do, think you have to worry about it!

    1. Worms are quite tolerant and resilient. You’re right, there’s no need to overthink things. But there are some simple things you can check and fix to help ensure your worms continue to thrive. It does not take much effort at all. For example, every Summer I move my worm farm inside. This is an easy way to help regulate the worm bin temperature. I don’t measure the pH acidity or check the moisture level in the bin of the bedding unless I notice something odd. I agree, if you have a die off, they will bounce back. When conditions become extreme, worms will fast track reproduction to ensure the survival of their species. And when conditions improve, the worm cocoons will hatch.

      1. There are some things that can completely kill a worm farm, which i did not know of before i started (currently running one for 12 years now).
        1. never ever feed them mint leaves. It kills them all. I assume this would also be the case a raft of other herbs that hold essential oils.
        2. place the worm farm at the south side of the house or shed so it doesn’t get battered by heat in summer. A whole die-off will result in a slurry of dead worms and goop coming out of the tap smelling like raw sewerage. Not something i want to experience again. A wet mat of wool and coir in the lower level helps a bundle!
        3. never ever add cat or dog poo (unless it is a separate system) If they have been wormed, it kills your worms. If they haven’t, then you may potentially have parasitic worms in the vermiculture. Neither is a good outcome.

  4. Hello,

    My worm farm seems to have alot of putrid, sludgy food in the centre that my worms don’t appear to be eating. When I pop a weeks worth of scraps in there (all fruits, veg and legumes) I always put some crushed dried camelia heads and leaves and once a week put a sprinkling of worm farm ph conditioner in too. Do you think I need to remove the sludgy food or will the worms eventually eat it if I cease feeding for a while?

  5. Why is my worm farm building up lots of fluffy white stuff, it started in a small spot & is slowly taking over?

    1. This sounds like mold. Generally, the occasional mold in a worm farm is perfectly normal and nothing to worry about. In fact, your worms will enjoy the extra food source. And mold helps in the process to breakdown organic material.

      However, excessive fungal growth is a sign of other problems. The main cause of fungal growth is overfeeding. When food sits for a while uneaten, it will obviously lead to some fungal growth. Fungi will also thrive in the acidic conditions which overfeeding creates.

      In the short term if you have a lot of mold in the bin, you can impede growth by mixing up the contents and adding some fresh bedding to soak up any excess moisture.

      In the long term, reduce the amount of food you add and offset any acidity with lime and fresh bedding for example.

  6. Very useful thread as i have to keep my stacking worm composter in my garage due to bears. I am having issue with fruit flies and smell so adding shredded paper.

  7. I thought lime/citrus was bad for the worms? I have a bug problem so in addition to adding more bedding I’m going to reduce the acidity. Should I just squeeze lime juice around or toss in cut pieces of lime? Also going to add more eggshells!
    I was under the impression that the liquid that comes out of the bin is amazing for our plants…but was informed the other day it should be discarded/not good to use in our garden??? What do you do with it?
    Thank you for your help! <3 Beginner gardener here!

    1. Hi Joleyne,

      Lime as in the mineral / rock – not the citrus fruit. Yes eggshells are high in calcium which will reduce acidity slowly over time. Excess liquid can be high in ammonia which is harmful to plants. I suggest you try and make some worm tea instead which is an excellent liquid fertilizer. Worm tea involves brewing or soaking finished worm compost in a bucket of water for a day or two. The key word here is finished compost.


  8. Thanks for taking the time to put this great resource together. I found a fix for my too wet worm farm and also how to fix the fruit flies. Much appreciated!

  9. I have a hungry bin and my bedding consist of alfalfa leaves, cow manure, coconut coir, and 95percent shredded paper. I had it sit for about two months before I used it to replace the bedding a month ago. I haven’t been feeding the worms because it is hot here in Riverside California and afraid that the bin will get too hot. with all that precaution, yesterday my bin was over a hundred degree and a lot of my worms escaped the bin and died. I am planning on taking everything out and add more paper to cool it down. will crushed oyster shell help with cooling it down too?

    1. Hi Oscar. Crushed oyster shells will help to balance the acidity levels in your worm bin. But it won’t do so much to lower the temperature. One of the great features of the Hungry Bin is it’s large capacity. This helps to regulate the temperature in the bin as it takes longer to heat up and longer to cool down. Manure is high in nitrogen which will increase temperature. On rare extremely hot days, I recommend adding a frozen water bottle wrapped in newspaper to create a cool zone. You can also add some dry bedding material on top which then acts as extra insulation. It’s difficult to lightly fluff up the compost in a Hungry Bin to increase airflow due to its continuous flow design which relies on compaction. Check out my Hungry Bin review.

  10. Hello, this is a very handy page. My worm farm has heaps of tiny snails in it, do you think this is a problem? Any ideas on how I can get rid of them.

    1. Hi Nads. Just keep trying to remove snails by hand. Apparently a snail can produce 100 eggs after mating. So you may want to consider starting again from scratch if the problem persists.

  11. Thank you for your very helpful tips. My worm farm has so many white pots worms and springtail bugs, as well as small grey things. They are present in the worm juice too in large numbers. The worms are still active. I have added extra crushed eggshells, lime, paper for a few weeks now and there’s been no improvement. Is the situation salvageable or do I need to start all over again with new bedding and worms?

    1. Potworms, sprintails & mites are harmless. You definitely don’t need to start over. Bugs come and go. If you ever have an outbreak of potworms, use some bread soaked in milk as a way to remove them. For the springtails, I’d try cutting back on food and water for a while.

  12. Thank you for the tip about placing frozen bottle of water in farm on a hot day. Yesterday, was extremely hot, a major bushfire disaster day in NSW. Today I found large clusters of worms near the bottle I put inside yesterday. In other parts of the bin are clumps of gooey dead worms 🙁 but at least some were saved. Thanks.

  13. I started my worm farm in late Dec 2019. I have three trays and top one is nearly full. How do I know when I can use the bottom one for compost and how do you remove the worms in it?? Also the top tray always has seeds that have sprouted is this good or bad?

    1. Hi Margaret,

      Depending on the size of your worm farm, you can expect to harvest your worm castings between 3-6 months. Try to leave the castings in as long as you can, before you need to change the trays. You can tell when the bottom tray is ready based on the consistency of the compost. It should be dark with no left over organic matter.

      There’s a few methods to separate worms from worm castings. Some are more effective at separating worms from finished compost than others. Personally I just throw all of the worm castings into the garden and rescue any stragglers. I recommend trying the dump and sort method. This involves dumping everything onto a sheet, creating mounds of compost and using sunlight so that the worms move towards the center. Then remove the outer surface of each pile. Repeat and sort.

      I wouldn’t worry about sprouts. It’s all organic. It’s easy to pull them out.

      Hope this helps, Daniel

  14. I’ve had a Hungry Bin for a number of years and seem to have a huge amount of worms. I have given some away but can I have too many?
    I feed them regularly so there is no shortage of food.
    Regards Margaret

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