A few weeks ago we had a sudden sweltering day – 89 degrees – after many cool, rainy days in a row. My kids were in our garage with some friends, pulling out some toys, when they came running and shrieking into the house, like banshees. My older daughter, the biggest chicken in the bunch, was claiming a wasp nest was in the garage and it was swarming with wasps. I went and looked though the window and it was literally blanketed not with wasps, but with flying ants. This photo was taken after they has dissipated somewhat and doesn’t do the number of ants justice. The window was covered with I would guess thousands of flying ants. I had never seen them before – they look like carpenter ants with wings.
I promptly shut the garage door, picked up the phone, and called my husband. I insisted he come home immediately, and to stop at the hardware store on the way home for a bug bomb, spray, whatever he needed to do. He was not nearly worked up enough (in many opinion) about the situation, told me to calm down, open the garage door so they could fly out, and he would see me at the regular time. Open the garage door!? That meant they would swarm our house, didn’t it? Well, I did it anyway and the ants did, in fact, disappear. My kids, meanwhile, felt the need to get suited up in “protective gear” before re-entering the garage to get their toys – armed with ski gloves, rain jackets, hats, and rain boots – on this 89 degree day.
After some research, we learned that the flying ants are basically harmless. We couldn’t find the nest but determined that there was a nest in the wall of the garage that needed to be removed by an exterminator. Here is a portion of an informative article I read:
By Whitney Cranshaw, Colorado State University Cooperative Extension specialist, entomology
Spectacular swarms of flying ants are a common summer phenomenon. Sometimes people will observe winged ants issuing in large numbers, pushed out by the wingless workers, from a colony established between a sidewalk crack or in a small mound. Other times only the winged forms will be seen, aggregating in large numbers around certain prominent points in the landscape.
Some background. Ants are social insects. The colony is established through the initial efforts of a mated “queen”, a sexually mature female. Originally winged, after mating she sheds her wings and the no longer used wing muscles are an important source of nutrients for her during the early stages of colony development. Very, very few queens successfully survive this period and establish a functional colony.
However, if the colony makes it through this period it can begin to grow. Wingless, non-sexually mature workers are reared which subsequently help expand the colony. After several years, the colony may be well-established and then some resources are put into rearing reproductive forms. These are the winged ants, some females – the potential future queens – and the majority males.
Periodically, usually following by 3-5 days a heavy rain, the winged reproductive forms emerge from the colony in large swarms. Such swarming behavior is usually synchronized by other nearby colonies so large numbers of winged ants suddenly appear. All mating for the species takes place, often over the course of a single day. The males die and the mated females disperse to attempt establishing a new colony.
One behavior associated with some ants during mating swarms is “hilltopping”. This refers to their aggregation around prominent points of a landscape where they search for mates. A large tree, the chimney of a roof or even a tractor moving across the plains might serve as such an “action site” for swarming winged ants. My favorite hilltopping site was the top of the US West tower in downtown Denver, which annually is the site for millions of harvester ants to aggregate.
Although dramatic, swarming ants pose no harm or risk of increased ant infestation. Those seen emerging from a colony were always there and are in the process of leaving the colony permanently. Mated females amongst aggregating masses similarly disperse from the area.
However, in rare cases winged ants are seen moving into the house. In some cases it is likely that an established colony exists within the home and may need to be treated. Carpenter ants and pharaoh ants are two species that can produce a nest within a building.
Other ants, such as the field ants, commonly nest outdoors next to foundations and may incidentally swarm indoors, working their way indoors through foundation cracks. And harvester ants in the midst of hilltopping behavior may fall down chimneys. In these cases there is not risk of permanent household infestation.
So the bottom line on flying ants? Somewhat alarming in appearance, but not too threatening:-).