So there's these really tiny, almost microscopic bugs on the lids of both of my hamster cages. They are basically the size of a grain of salt but sometimes being a little bit bigger and even smaller. They seem to be a grayish color but sometimes red which Im assuming is because they're biting the hamsters. They seem to only be on the lids but I will occasionally find them on the hamsters. One of the cages is a wire one and the other is a tank so it's not the cage and I've cleaned both cages and all the items thoroughly even wiping everything down with watered down listerine and putting chinchilla sand in the cage but after I clean everything like 2-3 days later the cages are infested again. What are these tiny bugs and how do I get rid of them?