Depends on the kind of ants and where they are. Some ants have quite a potent sting, and I once had a bed full of ants, even if there were the harmless kind, I didn't particularly appreciate having dozens of ants crawling on me at night.
Note: for the latter, I lived in an RV at that time, the bed was literally at arms reach from the kitchen. I tried to use insecticide gel, which ended up making the problem worse, as I now had dying and crazy ants falling down from the ceiling. Turned out the source of infestation was a dirty bike bag that ants turned into a colony, throwing it out solved the problem.
