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Flying ant day: winged ants swarming after rain in late August
When: July to September
On a warm day after rain in late August, ant colonies push out clouds of winged queens and males for a single mating flight; around Boston the star species is nicknamed the Labor Day ant.
Why this time of year
The end of August is this region's signature swarm window: warmth after rain triggers colonies across a whole neighborhood to fly on the same day, and each flight lasts only about a day.
How to notice it
- After the next warm rain, watch pavement cracks, curb edges, and sunny lawn patches for winged ants boiling up out of the ground.
- Confirm ant, not termite: bent antennae, a pinched waist, and front wings longer than the back pair.
- Watch a big female land and tear off her own wings; she is done flying forever and about to dig a nest.
- None of them sting; the flyers have one job today and it is not you.
Try this with kids: Can you find a queen on the ground pulling off her own wings?
a mating swarm is the one flight of an ant's life; queens fly once, then live underground for years
Safety
- Swarms outdoors are harmless; a swarm coming out INDOORS means a nest in the building and is worth an adult's look.
Sources
- extension.psu.eduAt certain times of year, usually early spring and late summer depending on species, winged ants leave the nest and swarm; females and males mate and the males die soon after; the mated queen flies to a nesting site, tears off her wings, encloses herself in a small soil excavation, and lays eggs; alarm at swarms mostly stems from confusing them with termites.
- wbur.orgLate-August Boston swarms are likely the Labor Day ant, which mates near the end of August; workers push the males and new queens out of the nest and send them off to fly; swarms occur in warm weather after rain and were seen simultaneously across Jamaica Plain, Cambridge, Somerville and more; they are not going to sting; the flights only last a day; queens rip off their wings, burrow in, and use sperm from that one flight for years.
- extension.umn.eduCornfield ants swarm July through September, especially on warm sunny afternoons, and field ants July-September; winged ants have a narrow constricted waist, bent antennae, and hind wings shorter than front wings, versus termites' rectangular body, straight beaded antennae, and four equal wings.
- extension.umd.eduAnts have elbowed antennae and a pinched wasp-waist while a termite's body extends straight back from the head; ant front wings are longer than the hind wings and tinted brown, while termite wings are equal, pale, and translucent.
In the guide for July, August, September