What Are Carpenter Ants? Should You Worry About Them?

Carpenter ants are dark, large ants from the Camponotus genus which get their name from their habit of excavating and nesting in wood. They target moist and dry wood for their nests and chew through them to create smooth and polished galleries in which they’ll live.

These ants are one of the most notorious wood-infesting or damaging insects alongside termites and carpenter bees, and can cause significant damage to wooden structures.

In this article, we’ll look into how to identify carpenter ants, learn about their habits, and determine if they’re a cause for worry. We’ll also check the signs of carpenter ant infestation, and finally, discuss how to get rid and prevent such an infestation.

How To Identify Carpenter Ants

Carpenter ants are large ants that measure up to 9.5-13mm long (⅜-½ inches) and can be yellowish red, solid black, or a combination of black, red, or reddish orange in color. 

They have dimorphic workers, meaning workers in the same species may be different in size and are categorized as either minor or major workers. 

Additionally, they also have winged reproductive ants (queens and males) which swarm to mate and establish new nests at certain times of the year.

Lastly, when viewed from the side, carpenter ants have rounded thoracic dorsums and one-segmented petioles. (view image below)

Carpenter Ants vs Termites

Due to their winged reproductives and wood-infesting nature, carpenter ants are often confused with termites. They are however, very much different physically and behaviorally. The differentiating physical characteristics are as follows:

• Carpenter ants have narrow waists while termites have broad waists.
• Carpenter ants have segmented and elbowed (bent) antennae while termites have straight antennae.
• Carpenter ants have differently sized wings with their front wings being larger than their hind wings while termites have uniformly sized wings.
• Carpenter ants are dark in color while termites are light or creamy in color.

Behavior wise, carpenter ants don’t eat wood while termites do. Also, carpenter ant infestations result in frass accumulation while termites leave fecal pellets instead. Finally, carpenter ants produce smooth, polished galleries in damaged wood, while termites leave mud-like material in the wood that they’ve damaged.

Carpenter Ant Habits

Where Do Carpenter Ants Live?

Carpenter ants may nest in soil, but usually nest in wood. More specifically, they prefer to nest in moist wood which favors the growth and development of brood. This includes different types of wood from indoor structures such as wooden frames, doors, walls, and roofs, to stumps, logs, and trees outdoors. 

What’s interesting about carpenter ants though, is that they establish multiple nests. When a colony matures, carpenter ant workers make nests called satellite nests around the vicinity of the main or primary nest. This leads to a major relocation of ant castes and individuals are moved accordingly. 

In the end, the primary nest houses workers, the egg-laying queen, and her eggs while the satellite nests house workers, drones, virgin queens, older pupae, and larvae. With this configuration, satellite nests don’t need as much moisture as primary nests and therefore, can be constructed in relatively dry locations.

What Do Carpenter Ants Eat?

Unlike termites, carpenter ants don’t actually eat wood. Instead, they eat pretty much what every other ant eats. As predators and scavengers at the same time, carpenter ants will consume both living and dead insects. For example, carpenter ants will usually feed on termites that they encounter when excavating and drilling through wood.

Carpenter ants also like to eat sweet sugary substances such as nectar, syrup, honey, and honeydew. In fact, carpenter ants are among the select number of ants that raid weakened bee hives for honey and nectar. They also form mutualistic relationships with aphids, as they tend to and protect them in exchange for honeydew.

When Are Carpenter Ants Most Active?

Carpenter ants are generally nocturnal, meaning they forage and do their other activities at night. Large groups of carpenter ants usually emerge from their nests 15 minutes before sundown and work throughout the evening using canopy patterns and man-made guides such as wall edges to navigate while foraging.

What Attracts Carpenter Ants Into Houses?

A few things can attract carpenter ants into a house, but the primary culprit is moisture. Carpenter ants love to nest in moist wood as not only is it softer and easier to chew on, but as already mentioned, it also favors the growth and development of their brood. So leaks or condensation issues could very well prompt carpenter ants to invade houses.

That said, carpenter ants do also nest in dry wood. Firewood, logs, and stumps are all potential nesting sites which may attract carpenter ants in and around a property.

Lastly, there’s food. Just like other ants, carpenter ants are very much attracted to food. Any spills or food left lying around are prime targets for actively foraging carpenter ants and may invite them into houses.

Should You Worry About Carpenter Ants?

You most definitely should. While carpenter ants aren’t necessarily aggressive and won’t usually bite unless threatened, they can be extremely dangerous when it comes to property and structural damage. 

When left unchecked, these ants can severely weaken the foundation and warp the frame of your home which may then lead to bulging walls, sinking ceilings, and an overall structure at risk of collapse.

Signs Of Carpenter Ant Infestation

Given the danger that carpenter ants present, it’s important to be on the lookout for any signs of infestation. These signs are as follows:

Ants

The most obvious sign of infestation is the presence of carpenter ants themselves. Regardless of their number or how regular they appear, their presence is a good indicator of an infestation. This is especially true when winged carpenter ants(alates or reproductive ants) or at the very least, their wings, are found in and around the property as that would pretty much suggest that a nest is nearby.

Frass Build Up

Another common indicator is the accumulation of frass or sawdust like cone-shaped piles of trash around wooden structures such as baseboards, window sills, and floors. This frass is made up of wooden fragments and other debris like dead insects that have been removed through nest openings as carpenter ants excavate wood.

Noise

Carpenter ants make noise as they excavate through wood. Though faint, they make audible rustling or scraping sounds from inside the infested wood. 

Damage

Lastly, and worst of all, is damage. Again, when these carpenter ants are left unchecked, they’ll cause damage to the point that a structure may collapse. They’ll leave damaged wood with smooth and polished galleries which at first may simply lead to hollow wood, but will eventually get worse and lead to weakened foundations and warped frames. 

Damage is a very late indicator of carpenter ants and ideally should never be the way to find out about an infestation. 

How To Get Rid Off And Prevent Carpenter Ant Infestation

As established, carpenter ants can be a serious threat to a property or other wooden structures. Should infestations go unchecked, these ants may cause severe structural damage similar to that caused by termites. Therefore, it’s important to treat and prevent infestations.

Treatment

The first step to treating a carpenter ant infestation is to locate the nest. That way, you could apply the necessary measures to effectively remove the queen and the whole colony. So check for moist areas such as sinks and tubs. Also check around firewood stacks, logs, and other wooden structures such as doors and windows. 

Once you find the nest, you may proceed with applying insecticide such as dust, aerosol, or foam, directly into the ant nest. In some cases, you may need to drill holes into the wood for better penetration as you’ll have to try your best to get rid of the whole colony. Leaving even a few of these ants behind may allow them to simply rebuild their colony and reestablish their nests.

For out-of-reach or hard to locate nests, you may opt to use baits instead. These baits are a mixture between toxic matter and food that attracts ants. They work as the ants themselves would take the bait to their nests and hopefully pass the toxin to the queen. That said, success isn’t necessarily guaranteed.

Therefore, most of the time, the best course of action is calling for professional help.

Prevention

First and foremost, check and correct moisture problems such as roof or plumbing leaks and drainage issues to prevent any wooden structure from becoming damp and attractive to carpenter ants.

Next, be sure to have clearance between soil and structural wood. Having wood in contact with soil may facilitate easy nest immigration. The same goes for tree limbs, branches and other types of vegetation in contact with the house. These limbs and branches may serve as bridges from carpenter ant nests to other wooden structures. 

In the same light, be sure to remove any unnecessary wood such as logs, stumps, and other debris. If you’re keeping wood of any kind, store them away from the property or other wooden structures.

Also remember that carpenter ants are also attracted to food. So be sure to clean up and store your food properly. Don’t leave dirty dishes out, and be sure to tightly close your trash cans.

Finally, try to seal cracks and crevices that may allow carpenter ants to enter your home.

Summary: What Are Carpenter Ants?

Carpenter ants are large and dark ants notorious for infesting and damaging wooden structures. While they’re not as bad as termites, these ants can cause significant structural damage when left unchecked and are most certainly a cause of worry.