Borax/sugar/water mix.

There is a bit of info online about it, you make up a solution, put it out in little containers (with the cat and baby maybe in a cupboard where the ant like to be or inside an old margarine container with a hole cut in or something) and like ant rid, they eat, take back to nest and pass on the poison to the nest.

You can get borax in the supermarket laundry aisle and when your ants are gone you can use the borax to make your toilet bowl cleaner, boost the power of your washing powder, take out stains, make Gak for the kids, experiment with crystals…. It is an awesome product!