What are these tiny black worms in the shower?

Question: We have these tiny little worms in the shower on the ledge under the shampoo bottle. They are black in color and when I pick up the shampoo they all begin moving. My husband cleans out our drains often. There is nothing to pull out of the drains you can see straight through. I clean again and again but they come back after several days. I scrub my shower tile grout with a toothbrush and bleach every other week. Why do we have these worms? And what are they? How can we get rid of them?

Answer: I think these are the larvae of drain flies / moth flies…but it seems you are doing everything right to get rid of them, so I’m lost as to what to recommend. The only possibility is that you have indeed eliminated the breeding locations, but there are still some of the adult flies around and they continue to lay eggs. make sure the windows are closed, and remove that shampoo bottle (put it somewhere other than the shower when not in use), the objective would be to remove all possible breeding sites.