Minnesotans are lucky. We don’t have to worry about wood-destroying insects like termites. Termites are rare to find in Minnesota, but when they are discovered, they are almost always brought in by receiving lumber and furniture from out of state. Termites don’t care what condition the wood is in. They don’t limit themselves to chewing through dry, rotted wood as Minnesota’s carpenter ants do. They chew right through drywall, carpet, and furniture. Luckily, this is not the case with carpenter ants. Carpenter ants chew on wood; however, as published by the University of Minnesota Extension, damage occurs slowly and often takes years to develop, depending on the size of the nest. Unlike termites that eat the entire wooden structure, carpenter ants only chew through it to build tunnels and galleries for their nests. They typically target already rotten, wet, and damaged wood, making their presence a clear signal to homeowners of underlying moisture issues.

Carpenter ants construct multiple nests per colony; one parent nest and several satellite nests. These satellite nests are more often than not the nest that is active inside homes and buildings. Satellite nests are home to worker ants, matured larvae, and pupae. Carpenter ants begin building these nests for the colony to grow. It allows them to retrieve more food by increasing their territory and finding a warmer spot to help with developing the ant’s larvae and pupae. The parent nests are home to the egg-laying queen ant, her larvae, pupae, and over 2000 worker ants. As the workers navigate between each nest, they are often spotted making their way inside of living areas. Some of the most common places to spot these colonies are around bathtubs and sinks, behind dishwashers, around poorly sealed windows/door frames, under roof leaks, and near poorly flashed chimneys—or any other area that is capable of releasing moisture. Wet wood is softer, making it easier for carpenter ants to chew through. Their nests can be found in old tree stumps, wood piles, and trees. Ants living in trees have a symbiotic relationship with them. This is simply natural ant behavior and does not mean they are killing the tree. Carpenter ants chew only on rotted parts and leave the living structure of the tree alone. By nesting in the rotted wood, carpenter ants are signaling that the tree is already damaged, which can further weaken its structural integrity rather than making it healthier. It should be noted that if the tree is completely rotted out, precautions should be taken by removing the tree before it causes damage to a structure or results in injury.

Carpenter ants come in many shapes and sizes. Some are larger than others and can be seen with wings. Worker ants can be between 3/8 to 1/2 inches long and are either all black or red and black. The carpenter ants with wings are larger and play a special role in helping build the colony. Seeing clusters of ants with wings indicates that they are preparing to mate. Both male and female carpenter ants can have wings, but females are generally much larger. A female ant or queen ranges from 1/2 inch up to 1 inch in length. Males are similar in size to the workers, distinguishable only by their wings. To mate, both male and female ants fly next to each other in an event called a nuptial flight. This occurs in late spring and early summer. Once the process is complete, the male has no further purpose and dies soon after, while the queen sheds her wings after finding a new place to build her colony. Eating her wings gives her the nutrients she needs to feed her first cluster of eggs so they can eventually become worker ants. It takes about 6-12 weeks for the queen’s eggs to turn into workers. Once they become workers, they will forage for food to feed the queen, enabling her to produce more eggs. The queen can live up to 25 years while hidden underground or in a tree, laying thousands of eggs daily throughout her lifetime. Targeting the queen is the only way to ensure a carpenter ant treatment wipes out the entire colony.