While there are several different unwanted pests that may find their way into your bin, the most common are mites. The good news is that, though they are unsightly, the mites that end up in worm bins are harmless to humans and house pets; however, you’ll still want to get rid of them. The presence of mites hints at several things that may be wrong with your bin: too much moisture, too much food, and a substrate that is too acidic. To counter these issues, reduce the amount of food scraps you add to your bin, and don’t add any extra moisture so that your bin can dry out a bit. To counter pH issues, mix some crushed eggshells into your substrate, which can help neutralize the soil making it less hospitable to mites.