Rotline Question: Why should I add eggshells to my worm bin?
Answer: Since worms don’t have teeth, they need “grit” to help with grinding and digesting their food. These are essentially small, hard particles that the worms swallow and store in their digestive tract in order to help them grind their food internally. Crushed eggshells are an excellent type of grit -- just make sure the pieces are small enough for your worms to swallow. This can easily be accomplished by placing dry egg shells in a plastic bag and then crushing them with a rolling pin. Or you can even use a coffee grinder, although you’ll want to clean it out before your next brew! As a final benefit, crushing your eggshells will also ensure that you have no large shell pieces in your finished worm castings.
In addition to the digestive functions described above, eggshells can neutralize pH in the worm bin, helping your worms avoid health problems such as protein poisoning (AKA “string of pearls”) that are caused by overly-acidic conditions.
The calcium in eggshells also helps keep your worm population thriving by contributing to reproduction. The exact reason isn’t fully understood, but worm farmers have long noticed a boost in reproduction after adding eggshells to their bins. Now you can spread the love by sharing your worms with a friend!