[Ant Control] Carpenter Ants & Houses: A Rotten Love Story

Features - Ants

Almost every ant you see is a female — a daughter of the queen and sister to the other ants in the colony. Here’s what you need to know to get these ladies out of your customers’ homes.

July 21, 2015

Carpenter ants are the incredible hulks of the ant world. If customers weren’t so mad that they were ruining their houses, they might be impressed. The teamwork! The strength! The incredible gall to bore giant holes into our houses that we paid for!

Knowing the hows, whats and whys of carpenter ant biology can actually help us help our customers prevent an infestation and pinpoint the vulnerabilities in houses that attract these talented little woodworkers.

Wood is Good.

Found in forest ecosystems and wooded areas around the world, carpenter ants serve a vital role in the decomposition of old and rotting trees. There are more than 1,000 species in the genus Camponotus; there are several pest species in the United States, the most common being the large, black carpenter ant (C. pennsylvanicus). But did you know that carpenter ants do not eat wood? They chew through wood to build their nests, where they bring all sorts of items back for the larvae and workers to eat.

These insects are true omnivores, meaning they eat just about anything. You’ll find foragers carrying seeds, flowers and insect body parts. In human dwellings they go for sugar, honey, pet food and crumbs from dinner.

Carpenter ants also participate in the tending of aphid herds. Many ant species maintain a mutualistic relationship with these tiny, soft-bodied insects. Aphids excrete a sugar water solution that ants find irresistible; the ants will stroke the aphids with their antennae, effectively “milking” them like little cows. In exchange for this bizarre behavior, the large ants fiercely protect the aphid colonies from predators. The aphid herds become a valuable and reliable food source for a carpenter ant colony. You might think that a tiny droplet of liquid is not as essential for an ant as say, a giant grasshopper leg or a seed. However, when we think of how an adult ant’s body is shaped, the biology becomes clearer.

Skinny Girls & Smoothies.

Almost all of your customers can identify an ant. Most people are aware of a few key morphological traits that help to describe that characteristic anty-ness. They have impossibly tiny waists, elbowed antennae and distinctive separations between the head, thorax and abdomen that help our brains say, “Oh, that’s an ant!”

There is a common misconception that the ants we see actually eat the things they carry. Adult ants, with their tiny waists (termed the petiole) survive on a liquid-only diet, because solid food can’t pass through the waist to the hindgut to be digested. And almost every ant your customer sees is a female — a daughter of the queen and sister to the other ants in the colony. They suck the liquid out of flowers, insect muscle tissue and even insect brains. Ants are basically skinny girls working hard and running errands fueled by smoothies and juice. So why do we see so many ants carrying solid food they can’t eat? It must be torture!

All of that solid food is brought back to the nest and fed to the larvae. Ant larvae are adorable little legless fleshbags. They wriggle around and are fed by adult worker ants that tend to them. The larvae chew on the solid food, swallow it and predigest it. They often regurgitate it in liquid form to help feed the workers and foragers! In fact, adult ants and larvae feed liquids to each other all the time through a special type of regurgitation called trophallaxis. It helps foragers communicate about food sources and helps nest mates chemically recognize each other.

This biological construct is the reason that many ant baits, lures and pesticides are in liquid form. It is an easy way to ensure that a control measure can reach to all sections and castes of an ant colony. Basically we use their biology against them to get them out of our houses.

Home Sweet Nest.

Wood that has been infested by carpenter ants is riddled with tunnels, called galleries, which branch off and often end in hollow chambers. The tunnels are basically little highways or hallways between different rooms in the nest. There are certain rooms for eggs, different chambers for the larvae and workers and separate areas for food storage.

The galleries are themselves an example of the incredible craftsmanship of these tiny animals. They are left smooth and refined, without the debris and mud often found in termite tunnels. The ants painstakingly excavate their tunnels to keep them clear. In fact, one way to identify a carpenter ant nest in your customers’ homes is by the conical piles of sawdust, frass (ant poo) and dead ants found near their entrance and exit holes.

Parent nests, where eggs and the queen reside, are created in a damp environment, but satellite nests are made in varied habitats and hold older instar larvae, pupae and workers. To connect these different types of nests, carpenter ants dig incredibly intricate tunnel systems underground. If a primary nest is in the home, the satellite nests can be away from the house and vice-versa.

If your customer sees a single carpenter ant in her home, it may not mean there’s a nest on the premises. The ants could have an access point into the house where they will forage for food sources up to 100 yards away from the nest! Access points include spaces in the foundation and even a tree branch that is touching the house.

Doctor, I’ve Got Ants!

Unfortunately, it can be difficult for ants to distinguish between rotting wood that is appropriate to nest in and rotting wood that is inappropriate (like houses). This is where some homeowners can get a little touchy. Carpenter ants prefer rotting or damp wood, especially for their parent nests. No homeowner likes to think their incredible investment is rotting away. They want to blame the rotting on the ants. While the ants can create further structural instability by boring holes and tunnels, they are actually a symptom of a larger problem in many homes. Since carpenter ants will only chew into soft, damp or rotting wood, they can be a signal the home has a leak or drainage problem in/under the house.

It’s best to start your inspection in areas that struggle with moisture — kitchen sinks, eaves, porches, decks and windowsills. This is where the presence of these ants can help us to find problem areas that may have gone unnoticed for years. These little wood-borers also are attracted to wood that was previously damaged by termites, because it is so soft. During a home inspection for a potential sale, even if there are no termites left, that wood they affected could entice carpenter ants in the future. (Who knew biology could help with future home purchases?)

Remaining vigilant (without paranoia) about moisture in and around the home will serve to make your customers’ houses less attractive to insects (like carpenter ants) and therefore more lovely and pleasant. Put yourself in the mindset of a carpenter ant as you check homes for damp and rotting wood — in fact, make yourself a smoothie and BE THE ANT as you walk around the house!


Kristie Reddick, M.S., is one of The Bug Chicks, a team of entomologists on a mission to change the way people feel about arthropods. She is an award-winning lecturer, educational media specialist and researcher focusing on the biology, biodiversity, and distribution of solifuge arachnids in Kenya. As a Bug Chick she is dedicated to showing young girls and boys that women can be smart, silly, successful, brave and beautiful in many different ways. Learn more at http://thebugchicks.com.