Carpenter ant facts and info

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Carpenter ants are a common sight in many homes, but their presence often raises questions and concerns.

In this article, we provide essential information about these insects, including their appearance, where they come from, how to spot signs of an infestation and how to get rid of them.

Key insights

  • Carpenter ants are large, nocturnal ants that cause damage by excavating wood to create nests. They pose no direct threat to humans or pets.
  • They are attracted to damp, decaying wood and can infest both moist and dry wood. Indoor nests often link to an outdoor main colony.
  • Signs of infestation include live ants, sawdust-like piles (frass), ant trails, damaged wood or foam insulation, and faint rustling sounds.
  • Large or persistent infestations may require the help of a professional pest control company.

What are carpenter ants?

Carpenter ants are one of the largest ant species, ranging from one-fourth to three-fourths of an inch in length. They are usually black or dark-bodied and are known for their strong, wood-chewing jaws.

Unlike termites, carpenter ants do not eat wood. They use it to create nests.

Despite their name, carpenter ants do not eat wood like termites — they excavate wood to create their nests, which can cause significant damage to wooden structures over time. Carpenter ants are nocturnal creatures and can establish multiple nests within a colony, including parent nests and satellite nests.

Carpenter ants can cause significant damage to wooden structures but aren’t a direct threat to humans or pets: They don’t carry diseases and aren’t known to cause any health problems. However, carpenter ants can bite if they feel threatened. The bite can be slightly painful because of the formic acid they release; it is not dangerous.

Carpenter ants have a diverse diet. Outdoors, they typically feed on living and dead insects, honeydew from aphids and other sweet bodily fluids from insects. Inside homes, they are attracted to meats, pet food, syrup, honey, sugar, jelly and other sweets.

Where do carpenter ants come from?

Carpenter ants can end up in your home in multiple ways. They are attracted to damp, decaying wood, making areas with water damage particularly vulnerable. Overgrown tree branches touching your home can also provide an easy pathway for these ants. They can also be brought indoors through infested items like firewood.

Carpenter ants prefer to establish their nests in moist, decayed wood, but they can also infest dry, undamaged wood. They often build their nests in hollow spaces such as wall voids and attic insulation, or in less frequented places like basements and crawl spaces.

Indoor nests are often satellites of the main colony located outside. Therefore, even if you spot carpenter ants indoors, the primary colony could be outside your home, which means you should thoroughly inspect your property.

How to spot signs of a carpenter ant infestation

Identifying a carpenter ant infestation early can help prevent significant damage to your home. Here are some signs to look out for:

  • Live ants: If you see large, black ants in your home, especially in the kitchen or bathroom, you might have a carpenter ant infestation. They’re particularly active at night, so try to do your ant hunting then.
  • Sawdust piles: As carpenter ants tunnel through wood to create their nests, they leave behind a sawdust-like material called frass. Finding such piles near wooden structures can indicate an infestation.
  • Ant trails: Carpenter ants often follow trails, which can be along the edge of the carpet, baseboards or other edges and corners. If you see a line of ants following a specific path, it's a good indication of an infestation.
  • Damaged wood: Look for wood with small openings, a sign of carpenter ants at work. This is often more visible in areas with high moisture levels.
  • Damaged foam insulation: Carpenter ants can also infest foam insulation. If you notice damage to this material, it could be a sign of these pests.
  • Noise: In quiet conditions, you might hear faint rustling sounds from the ants moving and working in the nests.

Carpenter ants vs. termites

Both carpenter ants and termites can cause significant damage to wooden structures, but there are key differences in their behavior, appearance and the signs they leave behind. Understanding these differences can help you accurately identify the pest you're dealing with and take appropriate action.

Carpenter ants are usually larger and have a distinct waist, whereas termites have a straighter, thicker body shape. In terms of behavior, carpenter ants excavate wood to build their nests but do not consume it and leave behind sawdust-like piles known as frass.

Termites eat wood and other cellulose materials, so they do not leave behind visible frass. You might notice mud tubes or soft, blistered wood as signs of a termite infestation.

Both pests require immediate attention, but the methods and treatments used to control them can vary significantly. Accurate identification is crucial for effective pest control.

» LEARN: How much does termite treatment cost?

How to get rid of carpenter ants

If you've identified a carpenter ant infestation, here are some steps you can take to eliminate them.

Reduce moisture

Since carpenter ants are attracted to damp environments, fix any leaks and ensure areas are well ventilated to reduce humidity.

Remove food sources

Keep your home clean, store food in airtight containers, and regularly vacuum to remove potential food sources.

DIY pest control

There are several do-it-yourself methods that can help control a carpenter ant infestation. These include using commercially available ant bait stations, putting down diatomaceous earth and mixing boric acid with sugar water and placing it near ant trails.

Professional pest control

If the infestation is large or difficult to control, consider hiring a professional pest control service. It can use a variety of methods, including insecticides and dusts, to effectively get rid of carpenter ants before they cause serious damage to your home.

» GET HELP: Best pest control companies

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    What do carpenter ants look like?

    Carpenter ants are one of the largest ant species. They range from one-fourth to three-fourths of an inch in length and are usually black or dark-bodied. They have strong, wood-chewing jaws.

    Can carpenter ants bite humans or pets?

    Carpenter ants can bite if they feel threatened. The bite can be slightly painful due to the formic acid they release, but it is not dangerous.

    How fast can a carpenter ant infestation spread?

    The speed at which an infestation spreads can vary, but carpenter ants can establish multiple nests within a colony, including parent nests and satellite nests, which can accelerate the spread.

    Can carpenter ants survive in cold climates?

    Yes, carpenter ants can survive in cold climates — they’re resilient and can adapt to various temperatures. However, they prefer damp, humid environments.

    Are there any natural predators of carpenter ants?

    Several insects and birds prey on carpenter ants. This includes spiders, some types of beetles and some birds, including woodpeckers.

    Do carpenter ants eat termites?

    Carpenter ants are known to prey on termites. They are opportunistic predators and may eat termite eggs, larvae and adults if they encounter them. Their primary diet consists of other food sources, however: living and dead insects, honeydew from aphids and various household foods.

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