Identifying Small Brown Bugs with a Black Head?

I found these teeny tiny bugs in the bathroom next to the cat's litter. They have a black head with a brown body. I also found one next to the cat's food maybe that one was a straggler. I have seen many in the bathroom. They hide under the tiles in the wall. I have been living in this apartment for a year, but I saw these little things after a month of being here. They are too small for roaches.

I blew up the picture, but they are extremely small, _ the size of the under score. I bought some diatomaceous earth online to get rid of them and put some eucalyptus oil down until I get the diatomaceous earth. What kind of bug is this?