Your bin stinks
A healthy worm bin should not have an odor. If you smell something bad, you are most likely overfeeding your worms. Too much food can deplete air flow and create an anaerobic environment. Take any undigested food out of the bin and replace it with new bedding.
Your worms are heading for the hills
If you see worms leaving the bin, they’re telling you that something is wrong. If it’s not too wet and you aren’t overfeeding, the problem could be the pH. Worms have very sensitive skin and cannot survive in acidic environments. This is why you should avoid feeding them citrus or other acidic foods like tomatoes. Your bin should have a neutral pH, which you can measure using a pH probe or test strips. You can add calcium carbonate materials such as crushed eggshells or agricultural lime to neutralize acidity and increase pH.
There’s a fruit fly invasion
Preventing fruit flies in a worm bin can be challenging. Feed your worms fresh food waste that’s cut into small pieces. The smaller sized chunks are easier for worms to eat completely before the food begins to decompose and attract flies. Make sure to bury your food items and cover the top of the material inside the worm bin with a loose sheet of newspaper. These extra precautions help to prevent fruit flies from ever being attracted. If fruit flies become a problem, you’ll need to get control of them. Fruit flies multiply quickly in a worm bin and can soon outcompete your worms for food. Start by reducing the moisture level in the bin, keeping the bedding just moist. Hanging fly paper or installing homemade traps can quickly kill adults, breaking the fruit fly life cycle.
Reddish brown and white crawly creatures move in
The reddish brown ones are mites, and they’re often found in worm bins. The white ones are most likely springtails. Both are fine, and will not harm the worms unless they begin to take over the bin. They both prefer wet conditions, so discourage them by maintaining a healthy moisture balance in your bin. If their populations increase, add bedding and provide food with a lower moisture content. Try adding crushed eggshells, once or twice a month, which will increase the pH. Drain the bin if necessary.