Feeding red wigglers to garter snakes is questionable. I often thought that if you have a snake that it would be great to raise composting worms. You would have a constant food supply but that doesn’t seem to be the case. Feeding red wigglers to garter snakes can be toxic!
- Stress from being handled
- To re-moisten its body when drying out
- Exposure to light
- Defense mechanism when threatened
Many people think that the yellow fluid is urine. It looks just like urine but it is not. It is called coelomic fluid and it can smell like garlic according to Edwards and Bohlen (1996). The evidence that the worms are toxic doesn’t seem to be consistent because some people report feeding them to garter snakes without any problems. Some pet manuals don’t make a distinction between red wigglers and night crawlers.
Evidence that feeding red wigglers to garter snakes can be toxic.
Lani Lyman-Henley who is a biology professor and snake ethologist wrote the following message to the gartersnake mailing list in 2006:
I can attest to the toxicity of red wigglers. I saw its effects myself on a pretty large scale in about 1989. I was told by our lab manager (an excellent herpetoculturist and published biologist herself) that she did find documentation (seconded by our vet at the time, also published in reptile veterinary work) that Eisenia species (compost worms, red wigglers) can produce coelomic fluids toxic to snakes (and I’m sure other creatures). It appears to be derived from their diet, but we never isolated how. We actually raised our own for some time, but gave up on pursuing this since it was just too risky and there were safe worm food sources available. Any Lumbricoid “leaf worms” are small versions of nightcrawlers that are just right for smaller snakes, and most of the soil worms you’ll find are relatives. I don’t really want to remember the dozens of baby snakes that literally puked themselves to death on just one meal of toxic worms. Even though we’d had many safe meals, not knowing what caused the one batch (same supplier, same packaged diet) to be so much more toxic, we didn’t want to risk it happening again.
It is too bad that red wigglers can be toxic to the garter snake. They are cheap, easy to buy and to raise compared to nightcrawlers (Lumbricus terrestris) and related worms known as leaf, dew and garden worms.
These are sources for this blog post: