We received a question from a reader recently who has been finding red worms in his sink drain. The reader describes his situation well, so we’ll quote (with a few minor edits) his entire email, after which we’ll get on to the task of identifying the worms in the drain: “These worms keep entering through the sink hole of my bathroom. I just pour water and wash them down the drain again. But still they manage to come up again. They crawl really slowly and they move away from the sink hole. I am scared that they might be harmful because their color is very red…..like blood sucking parasites! Please help. Let me know what these are and how you can get rid of them. Even if they aren’t harmful, I’ll be happy not to see them again.”