During the late summer and fall and also in late winter/early spring months, the invasion of flying yellow or reddish-brown to black ants is common. Also known as citronella ants, the winged female swarmers are golden-yellow while the males are black. Their nickname is the citronella ant because when crushed or alarmed, it gives off a pronounced citronella or lemon verbena-like odor. Homeowners often fear that these 3.0 mm to 5.0 mm long-winged insects are termites. However, in most cases, they are usually reproductives of either the smaller or larger yellow ant.
Although there is one species of subterranean termite living in Michigan that will swarm in the fall months, most termite swarms are active March to late May. This necessitates knowing the difference between the flying ants and flying termite species.
- Antennae: Termites have beaded antennae similar to keychains; flying ants have elbowed antennae with the bend at or near the middle.
- Wings: Termites have four wings, all equally lengthed and almost twice the length of their thorax. Though ants also have four wings, their hind wings are shorter than the front wings and are not twice the body length. Also, ant wings have prominent wing venation. The wings of termites have no prominent veins and resemble milk glass.
- Body shape: Ants have a three-segmented body, with their waists constricting like an hourglass between each segment. Flying termites have two body segments without the constricted waist.
- In most instances, termites shed their wings shortly after swarming.
Citronella ants typically nest outside next to foundations or under concrete or wooden slabs. They survive almost exclusively on honeydew, which is a sweet material made by root-feeding mealybugs or aphids. Therefore, workers seldom invade homes or structures in search of food in contrast to many other ant species. However, they may cause problems by pushing dirt through cracks in foundations and slabs. The winged yellow ants can and do cause concern when flying into living quarters, creating a termite-like fright. Also, a very large number of yellow ant reproductives (with wings) and the smaller workers (without wings) may congregate on the side of a building on a mild fall to an early spring day, which can also cause a scare.
Tips for Control
Colonies do not require professional pest control unless the swarmers enter a home or structure. Even in these cases, treatment may not be possible because it is difficult to know precisely where the colony is located beneath the structure. Sealing all cracks in the floor where the swarmers enter can stop the swarm from entering a home or building, but the ants will likely find other cracks. Any treatment of extreme cases will involve drilling and treating beneath the slab, thus requiring the services of an experienced professional.