Black house ants can and will bite humans. If you get bitten by a black ant, it'll feel like a small pinch. Because the insects are very small, you may not even feel them crawling over you and may not be aware of their presence until they bite.  Black ant bites do not often leave marks on your skin. It seems that workers gathering food don't bite, but the ones that do guarding work are. Black ants are not as aggressive as red ants.