Richard, Sara and others have given you good advice. I too, in the spring, went through a nighmare with ants. They were everywhere.

What worked with the cat dishes is the chalk line around their bowls. The chalk gets on their little legs and that's it.............

Is it me, or does this seem to be an unusual year for ants..........I have had a problem since the first of the year?

Do you have a pyrex baking dish - one of those 9 X 12 jobbies.....
when all else failed, I put the food dishes in that with water in it.