Sneaky

Try getting some silicone and seal every possible crack or crevice that they can come out of.

Except, you know, THAT crevice.

Terro liquid ant baits work well, try putting them anywhere you see them coming in. Borax powder (may find in soap section, can be used in laundry) along any windows, doors, walls with cracks. 409, Windex, etc sprays will kill them on the spot if you don't want to mess with insecticides indoors. If you have pets, keep their food dishes inside a bigger dish with water to act as a moat. Ants are attracted to leaky sinks and such too, so make sure your pipes aren't dripping.