There are 2 things I use to kill ants that are safe to use around pets and kids.
If there are a few ants that are annoying in the kitchen or on my trash cans, I dilute "Dawn (original) Dishwashing Liquid" in a squirt bottle ( 1 part Dawn to 6 parts water), this kills the ants instantly.
If we are being bombarded from all directions, then I buy Terro, these come in individual trays (6pack) or larger garden baits. The ants go nuts for it. Just sit them out, 1 or more, depending on how many ants you have and hundreds will come to the bait stations. Just let them come. Yes, even in the house. (They are in your walls.) Sometimes it only takes hours, some times a couple of days and you will have no more ants. They take Terro back to their nests or sometimes the ants go in and don't come out.
Pesticide or insecticide sprays and powders are not safe for pets, kids or adults. Always use a safe alternative.