With large font and an enormous amount of consecutive question marks, a reader wrote to us to ask about a black worm in her bathroom. The worm is about seven centimeters (slightly less than three inches) in length, which is relatively long for a bathroom pest. (Larvae, the most common creature to find in a bathroom in our experience, are generally several times shorter.) The reader says the worm has no “texture” on its body, by which she means it has smooth skin, and the worm evidently has a titanic tolerance for Raid and other insecticides, as it didn’t die after being continually sprayed for 10 to 15 minutes. The reader is wondering, one, what the long black worm is (if it even is a worm) and, two, where it came from.