The answer to this question will partially depend on who you ask. For myself I definitely consider all earthworms to be vegetarians. However I have seen people online talking about how they give their worms all the left overs from meals, including meat. I’ve not tried it before, but I suppose it could be worth doing a test bin to see what either red wigglers or nightcrawlers would do with some meat.
Vegetarian Earthworm Diet
So for my worms I only add things that were once growing in the soil. This include the peels, rinds, and seeds, as well as the actually fruit or vegetable that was leftover from meals. If they were in a salad and have some dressing on them I will put it in the bin, but try to avoid as much of it as possible. So no meat, no spicy food, and no onions.
I do include coffee grinds, which are a great addition and obviously also once grew in the soil. Also paper (as long as paper isn’t the only thing you put in the bin) is a great option too. So coffee grinds and the filter go right in the bin.
I’ve also see that the worms like egg shells, so I’ll break them up into very small pieces and put those in as well. Eventually they’ll soften up and get eaten.
An interesting food source
Something I recently saw online is that earthworms will eat the items in your vacuum bags. So hair, dust, and the other common things that end up collecting in your vacuum is fair game. Since I read this, I’ve not had to empty my vacuum bag but when it comes time I am going to try it. My one concern with this one is that it might dry out the bin a little so I would think a few squirts of water will really help if you are going to empty a big vacuum bag in your bin.
What do Earthworms Drink?
When it comes to drinking they aren’t going to the sink to lap up some water they way you and I would. They are going to absorb some moisture though their skin, and inject some that is part of the food they are eating. As long as the mixture in your worm bin is about as moist as a rung out sponge then you are all set. If it ever feels dry then a number of squirts of a hand spray bottle should do the trick.