have you ever been bitten by anything from your feeder rats?

I noticed some little bugs on one of my rat racks , I don't know what they are. They were very small , little black specks. I sprayed some nix solution all over the tanks after cleaning them and I haven't seen any since then , but I wasn't sure if it was going to work.

What kinds of parasites are ASF's , or rats in general, prone to having?
anything that will bite humans?