Over the past couple of weeks I've noticed these very, very tiny black bugs on the windowsills of the bathrooms in my house. I believe that they can only walk very slowly, but most seem to just sit on the windowsill unless disturbed. However, they've multiplied and I've started seeing them in places other than the windowsill and I can't seem to find any information online which is why I'm asking this question.

What is it? The only way I can really describe it... well, you know how some bugs just automatically look harmful and creep you out? Like wasps, hornets, mosquitos, biting flies and such? These bugs seem to be the opposite. When you look at them it just seems like they aren't harmful. Almost like these insects are the bottom of the hierarchy. Of insect power.
...I think that's the sleep deprivation talking.

Anyway, thoughts?