Jeffrey Hahn, Asst. Extension Entomologist
There have been questions lately about winged ants being found in and around homes and other buildings. Nearly all ant species in Minnesota (Pharaoh ants are an exception to this) produce mating swarms, i.e. winged males and females, at certain times of the year. These reproductives emerge and fly out of the nest, typically in large numbers. The males die shortly after mating with queens. The queens fly off in search for a suitable place to start a nest, although the vast majority do not survive long, being eaten or succumbing to the elements.
Upon landing, the queen breaks off their wings. As she starts construction of the nest, she lays a batch of eggs which she cares for until they mature into adults. From that point on, the workers assume all of the work responsibilities and the queen's sole job is to lay eggs. She is taken care of by worker ants and remains in the nest her entire life.
In Minnesota, there are two common ants that people see swarming in the spring, carpenter ants and pavement ants. Carpenter ant queens are typically black and large, about ½ inch long, although some species are smaller and can vary in color. However all carpenter ants have a one segmented node between the thorax and abdomen. Pavement ant queens are about 1/4 - 3/8 inch long, brownish and has a two-segmented node.
Finding a swarm of ants indicates a nest is nearby. However, a swarm, in and of itself, is not necessarily a problem. For the most part, like when they are found in your yard, they are not anything more than a nuisance. Under these circumstances, just ignore them until they go away on their own.
If winged ants are found indoors, then there is a nest inside the home. Correctly identifying the ant species will help determine the best control. Pavement ants nest in the soil under objects, like sidewalks, driveways, stones, and concrete slab construction of homes. When found inside, they are annoying but are not a structural problem. The only necessary control when pavement ant swarmers are inside is to physically remove them, especially if you only see winged ants and not any workers
Finding winged carpenter ants indoors is another matter. They nest in water damaged wood and can potentially damage buildings. You can be somewhat patient when trying to determine where they are coming from and attempting control but you should not ignore them indefinitely. Their elimination is best done by a professional pest management company.
However, sometimes a wingless carpenter ant queen is found walking around in or around a home. Because it is a carpenter ant, people are concerned about a nest being in the home. But remember that this queen has not established a nest yet and is still looking for a place to begin one. Her presence does not mean a colony is in the home. The only necessary control is to dispatch her.