Although I often see black bugs (Hemipterea: Thyreocoridae) crawling on flowers throughout the summer, this late-season individual seemed a bit out of sorts. I found him wandering around the base of a barn along with some boxelder bugs (Hemiptera: Rhopalidae: Boisea trivittata). Boxelders are famous for congregating en masse in and around buildings prior to winter, and perhaps this black bug was following suit. Or perhaps he was simply lost and bewildered in the autumn chill.
These tiny true bugs can be identified by their shining black bodies, broad oval shapes, and scutella (hard shells) that cover almost all of their wings and abdomens. Most have relatively smooth legs, but some like this individual have somewhat spiny legs.