We had ants last summer. They came in through the kitchen and a wall near the kitchen. We caulked it up so they couldn't get in, and the problem was solved.
This summer, we've had ants again. They primarily come in between the areas we caulked last summer (can't get to it with the caulk gun because of the radiator), and go after the cats' food. We've taken to only putting their bowls on the floor while we feed them, and then taking them away. This generally reduces the ants, but if we go away for a weekend and have to leave some food out, we get a lot of ants.
We've read/been told that poison (especially poison the ants will take back to their nest) is really effective, but we're concerned about using such a solution in our apartment because our cats like to cause trouble and get into things, and we don't want them playing with any poison.
What is an effective, cat-safe way to get rid of ants?