Little ants that think they can just dance their way into your house and set up camp!
We had an infestation of them last week. They must have been dancing ants b/c they moved in under the sub-woofer! I could not believe my eyes! After freaking out for a moment, I got the ant spray and vacuum cleaner and went in for the attack! (Once again, I did not get pictures of the battle scene - I was too busy.)
I sprayed to stop the "movement", then I vacuumed them up, emptied the vac into a bag, tied the bag and put it in the trash outside. I went back and did a thorough spray in several rooms and hubs later sprayed outside and in again.