Entomology (Study of Bugs)/sudden appearance of tiny black bugs..
about an hour ago I suddenly saw tens of tiny black bugs on my windowsill in my bedroom. They might have come from outside because I have had my window opened this afternoon and a couple hours last night, and I haven't had it open a lot before that due to the weather. At first I didn't see that they were insects because they are really small. (about one millimeter in diameter.) They walk really slow and I haven't seen them flying. They're really round and entirely black. I live in the middle of the Netherlands. (Sea climate similar to New York) I can't upload a photo right now, so I hope this is enough information.
Of course without seeing one I can only make a guess. Small bugs around windows usually turn out to be mites. They can get in through the window crack. Wipe them up and then rub a bar of soap on the sill and into the crack. See if this gets rid of them. Is there a birds nest close by outside your window? They often come from nests