Yesterday I discovered very, very tiny black bugs, some in small clusters, in my bathroom. At first glance, I thought it was dust and looked up to see where it was coming from. It looks like finely ground black pepper. Then, with the help of a magnifying glass, discovered they were moving. I found them on the toilet seat and back, on the edge of the sink, and the edge of the bathtub.
What are they and how do I handle this?