We recently received an email from a reader who found a small and thin red worm crawling on her shower curtain. The reader immediately goes on to say that she is “assuming the worm is a bloodworm,” and we think this is as reasonable of a suggestion as any. The reader planned to remove the small red worm from her curtain after her shower, but by the time she had finished, the bloodworm (sometimes written as “blood worm”) had disappeared. The reader thought that this might mean that the bloodworm “hitch-hiked a ride somewhere on my body,” which led to her question for us: are bloodworms harmful?

A reader wrote to us recently about worms he found in his shower. The worms are really thin and are of a reddish hue, and they are about two inches long, more or less. With these characteristics taken together, the reader reports that these worms look like particularly small and thin earthworms, just like the ones you see outside after it rains. What are these worms?