Hi David,

It's common for carpenter ants to invade homes in the spring in search of water and possibly food.  The critical thing with carpenter ants is seeing them during the winter months when it is too cold outside for ants to be active.  If you see them in the winter then it is very likely you have a nest somewhere in the house.  If you call a pest control company they will charge you a lot of money to spray insecticide around the perimeter of your home.

Here's some basic info on carpenter ants...

Carpenter ants, Camponotus sp. (Hymenoptera: Formicidae)

Carpenter ants are one of the largest and most common ants in Michigan. Unlike termites, they only nest in wood and do not eat it. Outdoors, they commonly nest in hollow trees and stumps. Finding them indoors during the summer does not necessarily mean they are nesting in your house, they may just be coming in from outside. However, the presence of carpenter ants in homes during the winter months, when it is too cold outside for ants to be active, is a very strong indication a colony of carpenter ants exists inside the building. When they do nest indoors, they prefer an enclosed space that remains wet or damp, more or less, or a permanent basis. Carpenter ants are attracted to excessive moisture conditions around windows, doors, showers, bathtubs, dishwashers, leaky pipes and drains, and under leaky roof shingles or roof vents. They have also been found in dry areas such as hollow-core doors and false beams, and blueboard foam insulation.

The presence of winged carpenter inside the home during the summer, does not by itself, mean you have a carpenter ant nest in your home. Winged ants are the reproductive forms of the colony and usually issue from the colony in late spring. They drop their wings soon after mating and begin to search for a suitable nesting site. They commonly enter structures but only rarely do they succeed in finding a nest site and most winged forms die before establishing a nest.

The best method of controlling an indoor colony of carpenter ants is to locate the nest and treat it directly with a persistent insecticide registered for indoor use. Insecticides labeled for this use include Ortho’s Home Defense Max. Most importantly, be sure to make any repairs, if necessary, to keep the area dry.

Another approach that is gaining strength in the pest control industry is to spray all possible entry points on the outside of the building (where sills and foundations meet, around doors, windows, vents and utilities) with fipronil (sold as Termidor SC or Taurus SC). Fipronil forms a non-repellent barrier that the ants cannot detect. Carpenter ants must leave the house to forage outside for food so they will pick it up when the come and go and spread it through the colony. Neither of these insecticides is widely available but they can be purchased over the internet or at John Deere Landscaping (formerly Lesco’s). Neither product is labeled for use inside homes and other buildings. Termidor and Taurus should only be applied during the warmer months of the year when the ants are active outside. Taurus is less expensive.

Both can be purchased online at:
http://pestcontrol.domyownpestcontrol.com/search?w=taurus%20sc
http://pestcontrol.domyownpestcontrol.com/search?view=grid&w=termidor+sc

Commercially prepared ant baits are available but I don’t know how effective they are controlling carpenter ants; they are probably more effective in the winter when the ant’s favorite foods are not available. One internet supplier of carpenter ant baits is doyourownpestcontrol.com. They sell at least three bait products for carpenter ants. I recommend trying the Maxforce Carpenter Ant Bait Gel first and see how that works before purchasing one of the others. See their carpenter ant baits at: http://www.doyourownpestcontrol.com/carp.htm

Finding the nest can be difficult since many of the ant’s favorite nesting sites are inaccessible. Begin looking in the rooms where the greatest numbers are found and observe where they go or come from. Carpenter ants are nocturnal and are most active at night. Carpenter ants are very tidy housekeepers and quickly remove wood shavings, food debris and dead co-workers from the nest area. In many cases, this nest debris accumulates in basements beneath the nest area, so look for accumulations of coarse sawdust and dead ants along and on top of basement walls and in cobwebs.

Be sure to read and follow all instructions and safety precautions found on the label before using any pesticide.

Best,

Howard

Thanks Howard, very helpful response.  

Sent from my iPhone



Let me know if you have more questions.  My direct line email is <personal data hidden>

Take care,
Howard