a few things we do:
-spray bottle with dilute dishwashing liquid - spray the ants and wipe the area down so it erases their trail.
-check for cracks that they might be coming in from and caulk them
-outside, we use a product called "Terro" - it's borax in a corn syrupy solution so it's bad for the ants but not as dangerous to other living things as other pesticides. They bring the stuff back to their colony so it gets back to the source. You can get it at places like OSH.
-I've also heard they don't like cinnamon, baby powder, lavender, or bay leaves - haven't tried these things and it probably depends on the type of ant, but they're worth a try and are fairly kid-safe.
personally, I'd avoid doing any spraying, b/c it's hard to tell whether there's any residue left behind that could end up on something that your kids gum on. I'd stick with things like the little ant traps where the poison is contained and can be placed in kid-inaccessible areas