Guide to the 6 Most Common Worm Bin Problems (and How to Solve Them!)

Red wigglers and compost worms can be incredibly easy to take care of when they are happy and healthy. When things are going well in your worm compost bins, red wigglers need to be fed 1-2 times per week, watered occasionally, and harvested every few months. There's really not much to having a thriving population once compost worms get settled.

When problems arise, however, it is important to act on them quickly. The worm bin problems that usually occur range from simple problems like odor and bugs to more serious issues like worms crawling out of the bin or worms dying. All worm bin problems are caused by human error and mistakes, so most issues are easily fixed with the right know-how and a little extra effort.

With the above in mind, here are the 6 most common worm farm problems, their likely causes, and steps to resolve:

Worm Bin Odors

When managed correctly worm bins should not stink or have any odor other than an earthy, soil-like smell. 

If your worm bin starts to smell like a teenage boy’s bedroom, the most likely culprit is rotting food. Over-feeding, or feeding the wrong foods, can easily lead to rotting food, which can lead to bug and critters in your worm farm and, even worse, create anaerobic conditions that harm or kill your worms. 

To determine if food is the source of the problem, dig around in the bin and give a few areas a sniff test. If you find rotting or older food, remove it and try to determine why the worms didn’t eat it (was it buried, or was it something they did not like). Try a light feeding with a new food source (fruit like bananas, berries, and avocados are always a beloved food of worms). For a more complete guide on feeding compost worms, check out our detailed article here.

If rotting food is not the problem, then the smell may be coming from dead worms (even a single dead worm can emanate a terrible smell!). Look around on the surface of your bin and in the bedding for dead worms - they may be white/gray if they have dried out since death. If you find dead worms, there is a serious issue in your bin that needs to be addressed immediately. We highlight the key steps in this article on worms dying in your bin. 

Worms Not Eating

Red wigglers and compost worms should be finishing each feeding in 48-72 hours. If the worms aren’t finishing each feeding in 2-3 days, or if they are not eating at all, then there are a few simple things to check:

1. Worm Population - dig around in the worm bin or worm farm and verify there are worms in your bin! Worms may have died or left the bin (if it’s outside), so check for worms first.
2. Air Temperatures and Seasonal Changes - Red wigglers and compost worms are less active in the very cold (below 45 degrees) and very hot (above 90 degree) temperatures. This means they will eat less as well, so the amount you are feeding the worms needs to be adjusted as the season’s and air temps change.
3. Food Types - It’s possible the red wiggles don’t like what you are serving up for them! Dairy, meat, and spicy/oily foods aren’t good worm food, so verify you are feeding the worms something they like and can easily eat.
4. Moisture - Compost worms are 75% water, so they need a moist (but not too wet) bedding to live in. If conditions in the bin are too dry or wet, the worms may grow lethargic and not be as interested in eating. Adjust your watering routine so that the bedding is moist like a wring-out sponge.

If none of the above issues are the cause of worms not eating, then there may be a more serious problem in your bin. Check out this article which has more tips on what to do when your red wigglers aren’t eating.

Fruit Flies, Mites and Bugs in Your Worm Bin

Worms and other insects have lived in harmony for millions of years, so a few insects and flies in your worm farm is usually not a problem. However, large quantities of fruit flies or mites indicate a problem with food, moisture, or pH levels in your bin.

Fruit Flies in You Worm Bin

Fruit flies are attracted to food and fruit in your bin, so the best way to discourage their interest in your bin is to feed amounts that the worms can finish in 48-72 hours (if the worms finish the food quickly the fruit flies won’t appear!). In addition, it is ok to sprinkle a little bedding over the food in your bin, just don’t bury the food or the worms may not eat it.

Mites in Your Worm Bin

White and red mites are common in many worm bins. White mites are not harmful and shouldn’t be a cause for concern. Red mites are more active and are considered to be parasitic to worms and their cocoons. 

Red mites are attracted to acidic pH and moist conditions. If red mites appear in your bin, water a bit less so that your bedding is lightly moist and also add crushed, rinsed egg shells to the bin. This will help raise the pH in the bin and create more adverse conditions for the mites. 

Aglime also helps raise the pH of worm bins and bedding, but aglime is very concentrated so only mix in a small pinch at a time. Adding too much aglime can swing the pH to alkaline and worms may start crawling out of the bin.

Worms Escaping or Worms at Bottom of Worm Bin

Having a few worms leave the bin on occasion is normal and shouldn’t be a reason to panic. However, if worms are crawling out consistently and en masse, then there is a problem that needs to be addressed immediately.

There are 2 main issues that cause worms to leave the worm farm:

1. Ambient Temperature - temps that are too hot (usually above 95 degrees) or too cold (below 45 degrees) can cause worms to leave in search of safer conditions. If this is the problem, the worm bin needs to be relocated where temps are more comfortable for the worms.
2. Issues With the Worm Bin’s Bedding - Poor bedding choices for a worm bin can harm worms or cause them to flee a bin. Common issues are pH-related (too acidic or too alkaline) or materials (like store-bought potting soils) the worms just don’t like. 

The best option is to avoid these problems in the first place by carefully selecting the bedding used. Fully composted fruits, vegetables, leaves, or manure are great options for bedding, along with coconut coir, peat moss, or shredded cardboard. A mix of these materials works well too. 

When in doubt about a material for bedding, we recommend testing it first or just not using it at all. Remember, “maybe” is usually no when it comes to bedding and feedstock for your worms!

If the worms are already in the bedding and you believe the bedding is the source of the problem, try extracting the worms from the bedding. If extraction is difficult (and it can be), then mix in as much of a good bedding source (from the list above) as you can. Worms may still flee for a while but they should eventually settle in with the new bedding mix.

No Babies in Worm Bin

If you aren’t seeing cocoons and babies in your worm bin, don’t panic! Many factors can influence worm reproduction, from temperatures to worm density in the bin. 

However, the #1 factor in seeing more baby worms and cocoons in your worm bin is the season. Red wigglers and compost worms mostly breed in the spring (late Feb-May) and the fall (Sept-Nov). During these timeframes you should say swollen clitellums (a milky ring) on the worms' necks as well as cocoons (tiny yellow-brown, lemon-shaped capsules) in the bin.

If you aren’t seeing swollen clitellums on the red wigglers or cocoons in the bin during the spring and fall, verify the worm population looks healthy (e.g., feeding on the surface, active when exposed to light, etc.). If the worms aren’t healthy this can impact their breeding activity. 

Otherwise, be patient! Healthy, active worms have evolved to breed prolifically and they will start as soon as conditions are good.

Worms are Dying in Worm Bin

Similar to worms escaping the bin, worms dying in the bin is a reason for immediate action! Death will present in 2 ways:

1. Worms are dead on the surface of the bin, or
2. You notice the red wiggler population in your bin has decreased considerably.

If worms are dying the most likely reasons are temperature (too hot or cold), moisture (too dry), or bedding in the worm bin. For temperature and moisture, simply relocate the worms to a better environment and ensure the bedding is moist like a wrung-out sponge.

Bedding issues include pH issues or bedding that is fully processed into castings. Worms can not live in their poop for too long so if they have processed all of the original bedding into castings it is time to start a new tray or bin, or at a minimum mix in “a lot” of new bedding (we recommend a new bin with new bedding).

For more on worm death and steps to address various issues, check out our in-depth post on worms dying in a worm bin.

Worm Bin Problems - Summary

Just remember that most problems in a worm bin are caused by human error and mistakes and stem from:

• Feeding Issues: Over-feeding your live worms, feeding them too frequently or before their last meal is fully processed, and burying food are common mistakes that can lead to insects or harmful conditions.

• Temperature: Exposing live worms to very cold (less than 40 degrees) or very hot (greater than 95 degrees) temperatures can cause the worms to die or flee (which means a quick death as they will dry out and die quickly once they've left their moist environment).

• Watering Issues: Adding too much water to a bin or having standing water in the bin can contribute to "sour" conditions that harm the worms over time. Conversely, letting the bin get too dry can kill worms very quickly (worms are made up of 75% water and need damp, but not wet, conditions to thrive).

• Bedding or pH Problems: Remember to carefully select proven bedding for your worm bin. Composted fruits, vegetables, and manure are great worm bin bedding options along with coconut coir, peat moss, and shredded cardboard.

Thanks for reading! For more information, feel free to email us at highfive@brotherswormfarm.com or check out the other troubleshooting worm bin problems in this series:

• Worms are crawling out of worm bin (part 2 of 4)
• Worms are dying in worm bin (part 3 of 4)
• Worm aren't eating (part 4 of 4)