UGH! I just hate those &$#*&$@ ants!! LOL LOL Like AmberLee said, we do get this problem for about a month once or twice a year. This last year was the worst for us!! Did you all know that ants are attracted to water? That's why you find them a lot in the bathrooms? YUK!! Who knew?
I usually go around the perimeters of our house and spray on the outside (use pet safe repellant). Around doors, windows...everywhere!! I have also used those ant houses inside, along with the repellant. Actually, and very surprisingly...we haven't had as much trouble with ants in our cat food dishes as we have had ants in the bathroom and in the kitchen!! I do have these bowls for my cats that we use, called 'fool-a-bug'. I got them at PetCo. That might be worth a shot too!
Good luck to all dealing with those 'ants marching'! LOL