The Best Ways to Get Rid of Carpenter Ants in Your Home

• Place bait traps near where you’ve seen ants. Make your bait with a mix of sugar and boric acid.
• Spray insecticidal dust or diatomaceous earth onto nests to get rid of carpenter ants in your walls.
• Clean your home frequently to remove the carpenter ants’ food sources.
• ​​Prevent carpenter ants from getting in by sealing cracks and holes around your home with caulk, trimming plants near exterior walls, and fixing leaky areas inside.

Killing Carpenter Ants

Place bait traps near ant trails. Choose a slow-acting bait so the ants bring it back to the rest of the colony in the nest. Set out the traps where you’ve seen ants the most frequently, such as your kitchen, bathroom, or attic. Replace the baits every few days until you don’t see any more carpenter ants in your home. Avoid using an insecticidal spray that immediately kills carpenter ants since the rest of the colony won’t be affected by it and it can cause them to spread out to build more nests. Bait traps are your best bet if you can’t easily find where the ants are nesting or if you don’t want to use chemical insecticides. If you have kids or pets, place the traps where they’re unable to access them since they contain mild poisons.

Make homemade baits with boric acid and sugar. Mix equal parts of granulated sugar and boric acid together to create a sweet bait that attracts carpenter ants. Put the bait in small dishes or bottle caps near the areas where you’ve seen the most ants and along any cracks where they get into your walls. Reapply the bait every few days until the ants go away. The ants are attracted to the sugar, but the boric acid penetrates their bodies and kills them. Boric acid is low toxicity, so it’s safe to use around pets and children.

Apply insecticidal dust to nests inside your walls. Drill holes in your wall 3–6 feet (0.91–1.83 m) on either side of where you’ve seen ants entering. Use a bulb duster to blow the dust into the hole to coat the ants. As the ants walk through the dust, they’ll spread the pesticides throughout the nest to kill the rest of the colony. For a non-toxic option, apply diatomaceous earth to kill carpenter ants instead. After you’re finished applying the dust, seal the holes with a dowel or small piece of cork and paint over it to hide your repairs.

Spray a residual pesticidal barrier around your home’s perimeter. If you want to get rid of ants outside, treat areas where you’ve noticed ants, such as nearby trees and shrubs. Then, spray the pesticide around the base of your home to kill any carpenter ants that try to get inside. Apply the spray 2 feet (61 cm) up onto your home and about 3 feet (91 cm) out from the wall. Pesticidal sprays are toxic, so avoid letting pets or children in areas that you just treated.

Keeping Carpenter Ants Out

Clean your home regularly. Ants need food and water sources to survive, so sweep your floors and wipe your counters to clean up the crumbs. Wipe up spills as soon as you make them so ants aren’t drawn to the spot. Make sure you also remove any clutter around your home to get rid of potential shelters for the ants. If you spill something sweet like juice or soda, rinse off the area with water or use another cleaner since ants are especially attracted to the sugar.

Wipe ant trails with a vinegar solution. Mix a solution that’s equal parts white distilled vinegar and water. Dip a clean cloth in the solution and wipe the surfaces where you’ve seen a trail of ants walking through your home. The vinegar’s strong odor will temporarily cover up the scent the ants follow so they can’t follow the trail.

Seal up holes and cracks in your home with caulk. Look for cracks around your home’s foundation, as well as around doors and windows. Apply caulk to all the openings until they’re completely filled in. and cracks around doors, windows, and any other areas where ants could get into your home. Install a screen door and window screens as an additional layer of protection from ants.

Remove natural debris near your exterior walls. Cut tree limbs so they aren't hanging directly over your house. Clean up weeds, leaves, wood piles, and other debris that's close to your house since they could be harboring a colony of carpenter ants. If you have firewood outside, keep it away from your home and only bring it inside right before you burn it.

Fix leaks and water damage around your home. Search for leaks in your home since carpenter ants are drawn to damp wood. Repair any leaky faucets and pipes that you find so they don’t cause any more damage. If you find any wood that’s been completely water-damaged, replace it so it doesn’t attract ants. Check your home’s exterior for leaks in your roof or clogged gutters that need repairs as well. Carpenter ants make their nests in damp wood since it’s easier for them to chew through.

Identifying Ant Infestations

Look for large black or reddish ants in your home. It’s easy to identify a carpenter ant since they’re one of the larger household species at up to ⁄2 inch (1.3 cm) long. They have 3 body segments, 6 legs, and 2 antennae with an elbow-shaped bend. While they’re usually black, carpenter ants may also look brown or dark red. Most carpenter ants are wingless, but some worker ants may have 2 sets of wings. The front set of wings will appear longer than the back set. If the insects you see are brown or tan, have straight antennae, or have 2 sets of wings that are the same length, then you may have found termites. Get rid of termites right away since they can cause even more damage to your home.

Inspect your home for piles of sawdust and dead insects. Look around the bases of your walls, in cabinets, and near countertops for piles of frass, which is the sawdust-like material left behind when ants bore into wood to make their nests. If you see this around your house, it's a telltale sign there are ants in your home.

Check wood for smoothly bored holes. If you suspect carpenter ants outdoors, check stumps, logs, and firewood for long slits in the wood that have smooth sides. Check the ground nearby for frass scattered around as well. If you suspect ants indoors, look for holes bored into hollow doors, cabinets, beams, and structural wood. Look for areas where the wood might get slightly damp, such as in your bathroom or underneath sinks, since ants like to build their nests in moist wood.

Listen for faint rustling noises in your wall. Put your ear up to your wall where you think ants are nesting. If you hear a faint rustling sound like something is moving around inside your walls, then you’re probably dealing with a carpenter ant problem. Check walls near windows and doors since they’re easy entry points for carpenter ants.

Follow ant trails to find their nest. Since carpenter ants are active at night, check your home after it’s dark with a flashlight. When you see a long trail of ants, try to find where they’re coming into your home since the nest or colony will be nearby. Keep watching until you're sure where the nest is located. Most times, you'll probably see them crawl into a space in the wall, a cabinet, or a door.