Brown, red, black, and everything in between, ants come in many colors and sizes. Wondering if you saw an ant or a subterranean termite? Ants have a narrow waist, giving them an hourglass figure. Termites don’t.
Seen an ant with wings—or more likely, a kazillion of them? Now and then, males and new queens swarm off to start new colonies. If its four wings are two different sizes, you’ve got an ant. Swarming termites have four long wings.
Where they live
Ants live in large colonies underground, in rotting wood, or in moist, protected places—under bricks or patio stones, for example. Carpenter ants are more neighborly. They’ll set up shop in your home if water or water-damaged wood is nearby.
What they do
Hard-working ants tirelessly clean up dead insects and dropped crumbs. The problem comes when they start cleaning your house too. Most will grab a crumb and head back outside to feed their friends, but carpenter ants prefer to build at the source and will excavate your walls to be near water.
How to deal with ants
Do two things to keep these tiny cleaning ladies out. First, make it hard for them to get in. Use screens and door sweeps. Trim branches that touch your house. Seal holes in your siding (like where pipes go through the wall). Second, no free lunch. Keep the counters clean, the floors swept, spilled sweets cleaned up, food put away. Fix leaking pipes.
Meanwhile, keep an eye on bathroom and kitchen walls, the trim around doors and windows, and the wall near appliances that use water—you’re most likely to find carpenter ants there. But they’ll even colonize a leaky roof.
Got a problem? Learn which ant you have so you can get the right baits. (Call your county’s Cooperative Extension office.) Give baits time to work. Don’t wipe up around bait stations—ants follow each other’s scent trails back to the nest, taking bait with them to feed their fellows.
Ants in Houses Fact Sheet, 68k pdf file, at Cornell's Insect Diagnostic Laboratory