Ant Control

Why ants come inside

Most ants seen in Colorado homes do not live there. They nest outdoors, often near the foundation, and come in looking for food or water. A crumb on the counter, a pet bowl, a leaking pipe under the sink or the sweet honeydew that aphids leave on houseplants is enough to start a trail. Once a few workers find something, they lay a scent trail and others follow it. That is why ants seem to appear all at once, and why wiping up the trail with a household cleaner helps after the food is gone.

Which ant you have matters

Different ants need different treatments, so the first job is identifying them. Pavement ants are small, dark brown ants that push up little piles of soil at cracks in driveways and sidewalks, and they are often the ant people notice most in Colorado. They like greasy food. Field ants are larger, black or reddish ants that come inside mostly in spring, when the soil warms but the weather is still too cool for normal foraging outdoors. Odorous house ants have only recently been found in Colorado. They are small and black, smell a little like coconut when crushed and have been linked to heavy wood mulch against the foundation. Pharaoh ants are tiny, pale ants that can nest indoors, mostly in apartments and larger buildings. Carpenter ants are the largest ants here and are most common in wooded areas. The ones found in homes are usually foragers from a nest outside, but a colony can settle in wood that has been damaged by water.

Why we use baits

Spraying the ants you can see kills those ants and little else. Most of the colony, including the queens, stays in the nest, which may be a few feet underground. Colorado State University Extension notes that baits usually give the most satisfactory control. Workers carry a slow-acting bait back to the nest and share it with the rest of the colony. For pharaoh ants, spraying can make things worse, because the colony can split and scatter. So we place baits the ants will actually eat, sweet or greasy depending on the species, and keep sprays away from the bait. Outside, a treatment along the foundation can cut down on ants coming in, but it typically lasts from about a week to a month, so it supports the baits rather than replacing them.

Carpenter ants and termites

Winged ants swarming in spring are often mistaken for termites. Ants have a narrow waist, elbowed antennae and front wings longer than the back ones. If you find winged carpenter ants inside, or small piles of sawdust in a closet or crawl space, the colony may be inside the house. We look for the moisture problem that let them in, such as a leaking roof, a clogged gutter or wood touching the soil, because the ants will keep coming back to damp, soft wood until it is fixed.

What you can do

Keep food sealed, fix drips, rinse out recycling, pull heavy mulch and ground cover back from the foundation and do not spray store-bought products near our baits. Most ant problems settle within one to two weeks of baiting.