When we lived in NY, they were called Sugar Ants, here in Central PA, they call them piss ants. We used a product called Terro - worked great! Gotta find the nest, if possible to totally eradicate the problem.
You can search the web for more info - people say to draw a line with chalk, or cinnamon or other spices around the area. They say that the ants can't get over that type of barrier. (I will tell you that this didn't help us one bit.)
Get the Terro product & also try to find the nest. GOOD LUCK - they really are the MOST annoying things EVER!