It's getting towards the end of summer and ants aren't coming into homes as badly as a few months ago; many of them are relocating to newly populated university dorms, others are moving back in with their parents. But, if even there are only one or two colonies near your home you'll want to be prepared.
Outside of paying someone to dump large amounts of chemicals in and around your home, the next best thing is building ant traps. They're cheap, effective, and make a suitable low-rent ant farm for the kids to watch. Just don't let them touch it.
To make them you will need:
1 bottle of Terro™ liquid, available at most any hardware store's gardening department.
small (2" x 2" x 2" or so) plastic containers with lids
enough cotton balls to fill said containers
a drill, nail or something you can use to make 1/8" holes
WARNING You're working with chemicals here so be very careful to follow the safety instructions on the Terro™ bottle. Keep all kids and pets/animals you let live in your house away from the traps once they're made. Make certain you place the trap somewhere it can't be gotten to by inquisitive dogs, cats, birds or very clever fish.
For owners of especially sensitive animals (e.g. parrots), don't worry. The liquid doesn't give off fumes so it's safe for use around them. Provided they don't actually get into the traps themselves (but you could have figured that).
1 Open the containers
2 Drill about eight 1/8" holes along the bottom edge of the containers (where the sides meet the bottom; definitely not straight through the bottom or high up the sides); I'd suggest one in each of the four bottom corners and then one midway between each of the corners.
These holes are where the ants come in. If you want, decorate the entrance with an amusingly morbid message to the ants. Don't worry, few ants have the ability to read and even fewer have a well-developed sense of humor.
*hint!* Drill from the inside out, not from the outside in.
3 Line the bottom of the containers with one layer of cotton balls
4 Drip enough Terro on the cotton balls to just get them soaked, but don't overdo it
5 Add another layer of cotton balls, soak it with Terro
6 Continue adding layers of cotton balls and soaking with Terro until the cotton balls reach the top of the container
7 Put on the lid and secure it
*hint!* If you have pets, you might want to tape the lid down to make sure it can only be opened by animals with opposable thumbs
8 Place the trap as near as possible to where the ants seem to be coming in
At first you'll see a lot more ants coming in. Way more. But have faith! Notice now they seem to be only interested in your trap, which will soon be filled with hundreds of wriggly little dudes gathering up, well, poison which they'll take back to the ant hill.
After a day or so you should see few, if any, ants at that location. A few days after that the trap will probably have dried out. To replenish it you'll need to remove all the old, dry, sticky cotton that's in there and start again making layers, soaking, etc.
And that's it; couldn't be any simpler. Happy ant doom-bringing!