The Ants Came Marching In

The State of Washington has a problem with carpenter ants, specifically, the Camponotus modoc and C. vicinus species. These species commonly nest in standing trees (living or dead), in stumps, or in logs on the forest floor. The State of Washington has many forested areas which are home to dwellings that were built in the middle of some well-established, hard-working ant colonies. Many homeowners have insisted that the least number of trees be removed during the construction process. This creates a nice forest feel to the landscape, but it also makes an inviting place for these ant colonies to build their new homes or create satellite communities. If you think you may have an ant infestation, the sooner you tackle it, the better – especially if you plan on selling your home any time soon! A good home inspector will identify this problem and in the long run it will be less expensive to take care of prior to the home inspection.

Carpenter ants do not actually eat wood, they hollow out sections of wood to build their nests. They look for wet, compromised, rotting wood, as it is softer and easier to chew through. However, once they begin building a nest, they can extend into drier wood, which then creates an even bigger problem. They create tiny grooves in the wood called “galleys” which are actually passageways. If an infestation is left untreated and ignored, it can become a severe problem.

The following could be a good indicator you have a problem with carpenter ants:

  • What appear to be piles of saw dust. This artifact is called “frass”, and it is usually found in areas where the walls are damp or water damage is occurring.
  • Tap on the walls where you suspect the ants may be nesting, as this can cause a faint, rustling sound, which would indicate movement of the ants.
  • Look for worker ants, as they are a pretty good sign that you have an infestation, but sometimes they are just foraging for food and water and may not have a nest in your home.
  • Usually carpenter ants look for food in the dark, so have a flashlight handy. If you spot a worker, follow them to the nest.

If you determine that you have an infestation, there are several ways to remedy the problem:

  • To kill the ants, you can use carpenter ant bait, which will attract the ants and they will take it back to the nest to share with the colony.
  • Pesticides and insecticides are a good choice if the ant bait is not working. If you are using this remedy, remember you have to treat the actual nest or colony, not just spray an area where you think they may be living. This is best for an outdoor infestation.
  • If you have an indoor carpenter ant infestation, it is a little more difficult to treat on your own. It is probably best to call a professional exterminator, but if you are willing to expend some time and effort, you could do the extermination by yourself. To do this you would need to know the exact location of the nests and drill into the wall between 2 and 6 feet on either side of where the ants enter the wall. Then you should use an insecticide aerosol, dust or foam treatment around all of the holes and any other potential openings that the ants could use to enter the wall. If you decide to treat the infestation this way, you should be cautious and keep children and pets away from the treatment, as the insecticide could be poisonous to them.
  • There is a natural treatment for ridding your home of carpenter ants. If you wish to avoid the pesticides and poisons you can try some alternative remedies that are safer. You can make your own home remedy of baited food by mixing 1 part boric Acid with 10 parts sugar water, added to the food you are using as bait and put it out where you see carpenter ant trails or places where their foraging worker ants are often spotted. The sugar in the mixture will attract the workers and the boric Acid will kill them – and their nest. This process may take a bit longer to work and you will probably have to repeat it a few times before the entire colony is gone. You can also spray boric acid onto any ant nests or anywhere ants are likely to travel, as this will poison them. One other natural treatment is diatomaceous earth (DE). You will want the food-grade DE, which is completely safe for children and pets. Ants are attracted to it, as it is actually a soft sedimentary rock that is made of fossilized algae-like plants. They will eat it but cannot digest it, so it dehydrates them and shreds their bodies. You can destroy a colony of carpenter ants by dusting food-grade DE over their nests or injecting it directly into their nests. Again, because this is a natural treatment, it may take several applications before the colony is gone.

Of course, avoiding an ant problem before it gets to the extremes of having to treat it is the best avenue. Proper home maintenance such as fixing leaks and staying on top of any moisture problems will keep you from attracting carpenter ants. Your yard should always be clear of rotting and decaying wood, which is the perfect environment for these pests. Also remember that fire wood can harbor a nest, so be sure to inspect it before bringing it in the house. Staying on top of the situation is the best way to eradicate and avoid problems for the future.


  1. I like how you mentioned that small piles of sawdust can indicate a problem with carpenter ants. I noticed something like this in my dining room the other day, and I wasn’t sure where it came from. Perhaps it would be a good idea to have a professional come and inspect to see if I have a carpenter ant problem.

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