“I found this worm in my toilet bowl”, states this reader in Turkey about the red-striped worm pictured below. “I had not used this toilet for almost 24 hours. It looks like an earthworm. But I also wonder if it could be some sort of parasite. Thanks for any comment.” Based on the excellent image our reader sent in, we would say this is an earthworm, specifically a tiger worm. These creatures, otherwise known as red wigglers or red Californians, are completely harmless creatures, just like the common earthworm. They are not parasitic, and they do not bite or sting, so our reader needs not worry for her health and safety.