Ants are really smart

Okay....we just moved into a new house and apparently it is already occupied. By ants. Thousands, maybe millions of them. They are mostly outside, but I've discovered 2 things they really like: 1) whatever is in the bottom of the cup Luke has been drinking out of and left on the counter and 2) cat food.

Here's the question I have for you? What kind of brilliant communication does it take for one ant to find 3 pieces of cat food and notify 157 of his closest friends, who arrive on the scene within 3 minutes of his call? How's that work?

And what is the best way to evict these critters? Any suggstions?