Carpenter ants

Although we have a page at our web site about ants, there is so much interest in Carpenter Ants that it was necessary to add this page.

Carpenter Ants are often referred to as "black ants" or "big black ants" although some species are not black and they are not always large.  In reality, there are thirty possible sizes for carpenter ants.  Larger ants indicate a more mature colony: one that has been located in the same area for some time. 

Ant vs. Termite 

There is much confusion about winged ants.   Carpenter ants, as well as other ants, have a stage of development known as the reproductive or swarming stage.  Flying ant reproductives are often confused with winged termite reproductives.  

As a simple rule of thumb:  if the body of the insect looks just like an ant with wings, it's a flying ant, not a termite.   Here is a comparison:

  • Ant reproductives are defined by having three distinct body segments (head, thorax, abdomen), elbowed antennae and clear, pointed wings that are slightly longer than the insect's body.  
  • Termite reproductives have two distinct body segments (head & thorax), straight antennae and  translucent, paddle shaped wings that are twice as long as the body of the insect.

Inspection Clues

Carpenter ants are very common in areas that have a high water table.  They seek out high moisture areas in and around structures.   Though not always the case, when carpenter ants are found in a structure, they are there because of a moisture problem somewhere inside or adjacent to it.

Carpenter ants usually nest either in damp wood or close to it.  They may also be found in hollow areas such as hollow doors and curtain rods.  Ants will nest in attics near clogged gutters or areas that have been subject to water leaks.

Wood found to be infested with Carpenter ants often has been damaged by wood rot.  Wood rot is caused by fungus, a living organism. Wood rot destroys the structural soundness of wood.  These ants compound the problem by chewing into and nesting inside the wood.

Ants living in the wood smooth it out with their chewing mouthparts and then live within the galleries they create to take advantage of the high moisture content that they favor.   Unlike termites, carpenter ants cannot digest the cellulose in wood and thus do not destroy the wood in the same way as termites.

Conducive Factors

Some things to check for when there is a carpenter ant infestation include:  

  • leaks from the roof or gutters or downspouts
  • improperly caulked windows and doors (including patio doors)
  • water entering around window air conditioner frames
  • plumbing leaks
  • leaking dishwashers or washing machines
  • improperly caulked bathtubs, showers, sinks or improperly grouted tile showers.  
  • firewood stored in or near a structure
  • rotted railroad ties, decks or fences
  • overhanging tree limbs, etc.

This list is not complete, but provides the most common things to check to help minimize attracting ant to a structure.


New Technology Points to Baiting

As with cockroaches, baiting for ants has become a very popular.  There are a number of reasons.  First, baits are much less toxic than sprays and relatively small amounts of product are needed to for the treatment.  Next, baiting can eliminate ant colonies while sprays simply kill individual workers.  Ant colony are likely to produce more workers to replace the others which means that spraying for ants becomes a quarterly requirement.  Finally, baits are usually less objectionable because they are either odorless or have very little odor.  

Granular Baits   

We offer bait product that is effective against carpenter ants and other ants species.   Advance Carpenter Ant Granular Bait has a distinct fish like odor that is very attractive to ants, but may be objectionable to some people if applied indoors.  It can be used selectively by applying into only into cracks and crevice using a paper cone to deliver the granules into those areas. The bait must be applied carefully since it may be attractive to pets.  The manufacturer recommends an outdoor application of this product.  This often works well since ants will forage from the outside to the inside of homes. 

For best results, apply the bait in small piles to encourage the ants to return for more. Put the product out late in the afternoon or early evening (when the ants are most active) to increase the likelihood that they will find and move all of the bait that's been placed on the ground to their nesting area.   Spend a few minutes finding areas where ants are actively foraging.  Placing the bait in these highly trafficked areas will provide the best acceptance of the bait and ultimately kill the ants living nearby. 

Advance bait is not weatherize.  Therefore, timing of placements is necessary to avoid rain that may affect the attractiveness of the bait.  Our customers have told us that this product is very effect and others have told us how interesting it is to watch the ants move the bait around!

Another granular bait that is available for carpenter ants is Ni-Ban FG Fine Granular Bait.  This product is a food based bait impregnated with 5% orthoboric acid.  It is a low toxic formulation that may be effective in a number of situations.  Because it is weatherized, it may used indoors or outdoors.   Ni-Ban FG is sold in a squeezable applicator bottle.

Ni-Ban FG Granular Bait is not applied in piles as with Advance Carpenter Ant Granular Bait.  It may be scattered outside near the foundation.  It may also applied indoors in cracks and crevices or in other inaccessible areas.  It may also be placed on removable trays in areas that are not accessible to children or pets.

Finally, we have also offer is Maxforce Complete which contains hydramethylnon as the active ingredient.   This product contains a variety of grit sizes to appeal to a range of ant species.  This product is also weather resistant.

Gel Baits

There are a number of ant gel baits available, but based on feedback from our commercial applicator customers, the Maxforce Carpenter Ant Gel is the one to use.  As with all ant bait products, it is important to spend time locating areas where ants are foraging.  This product can be used indoors or outdoors and has no objectionable odor.  However, the active ingredient, fipronil, is temperature sensitive and should not be placed where temperatures will exceed 100 degrees Fahrenheit.   Also, as a sticky gel, bait will need to be selectively in places away from dirt or dust.

As with other bait products, don't clean or otherwise disturb the areas surrounding the bait placements.

Ant Bait Stations

Ant bait stations, which are commonly called "traps", are actually small containers that hold a semi-moist bait product which is accessible through small openings in the sides of the station to allow ants in to feed.  Bait stations offers the highest level of safety because the pesticide is well protected within the station keeping children or pets from contact with it.  

However, the bait in stations is not as attractive product since it not as moist as gel and Carpenter Ants, in particular, seek moisture.  But we have had people use bait stations successfully for controlling carpenter ants as well as for other ants species.

For those that wish to use a bait station, we offer Maxforce FC Ant Bait Stations.   Note that due to a technicality, the current product does not list carpenter ants on the label.   However, the identical product was labeled for that species for many years.   Because of this, we are not permitted to recommend its use for control of carpenter ants in some states.

Always Use Caution

There are advantages to using baits, but though they are low in toxicity, they still need to be applied with care.  As with any pesticide, we urge everyone anyone that may apply these products to read the product label.

Spray & Dust Applications

If baits are not appropriate for your situation,  we continue to recommended a perimeter treatment for Carpenter Ants.   Customers have purchased this type of product from us year after year with continued success in minimizing ant problems (see  Permacide P-1 on our products page).  Our suggested treatment is as follows: 

Apply a pin stream (jet) application to the outside of the structure along the junction of the foundation and the building siding or shingle.   Also, treat around all window frames and doorframes at ground level.  Treat any deck or other wood that contacts the structure along the contact areas.  Treat any area where utilities such as plumbing or air conditioning lines enter the structure at ground level.

On the inside, treat baseboards along exterior walls, window frames and door frames, the sill plate downstairs (if it's accessible), around bathroom and kitchen fixtures and where plumbing enters those rooms.  Also treat around and behind kitchen appliances paying special attention to the dishwasher area.  You may need to remove the kickplate at the base of the dishwater in order to treat that area properly.

The concept is to set up an insecticidal barrier that will kill ants from either side of the foundation.   We have observed that a partial treatment is frequently not effective.   It's also important to note that applying a lot of spray is unnecessary: once you've wet the surface, it's treated.   Also, don't waste spray killing individual ants - if they contact the areas you've treated, they will die - even if they don't die immediately.  Finally, most of the liquid sprays are residual and thus are effective for several weeks;  it is really not necessary to spray more frequently than once per month.  We actually recommend one treatment every three months (once each season) for good control.

Though we find the liquid sprays work well, some people prefer dust products.   Dust products may be selectively applied into infested areas.  They may also be applied by drilling small holes into selected areas to provide access to an active area.  Boric acid dusts as well as Alpine Dust Insecticide or Drione Dust may be used this way. 

Talk to Us

If you have more questions about Carpenter Ants or our product line, you may call us toll free at 800-433-1128 or our local number: 845-356-2837.  You can also write to us via E-Mail by clicking here.  If you do not receive a reply, please let us know by resubmitting your letter.  We get a huge amount of unsolicited mail and we may accidentally overlook your inquiry.