Flying Ant Day, Explained

They are the same ants

Winged ants are not a separate species and they are not an invasion. They are the reproductive castes of a colony you already have: new queens and males, produced once the nest is mature enough to afford them.

They leave to mate in the air. The males die shortly afterwards. The mated queens land, break off their own wings, and look for somewhere to dig in and start a colony, which is the part that concerns anybody with a new patio.

The ordinary workers you see the rest of the year are sterile females from the same nest. Same colony, different job.

Photographs on this page are for illustration purposes only.

Why they all go at once

Because it only works if they do. A queen has to meet males from other colonies, so the flight has to be synchronised across an area, and the trigger is the weather.

What sets it off is a warm, humid, still day, usually after a spell of rain, typically in July or August. Every mature colony in the district is reading the same conditions and goes on the same afternoon, which is why it feels like an event and not a process.

It is not a fixed date and it is not one day nationally. It rolls across the country with the weather, and a cool showery patch will hold it up for a week.

Emerging outside vs emerging inside

This is the part that matters, and the two cases are completely different.

Outside, in the garden, off a patio or a lawn: normal, brief and not a problem. It lasts an afternoon, the birds have a very good day, and it needs nothing done about it. It does tell you there is a mature colony there, which is worth knowing if it is under your paving.

Inside, coming out into a room: that means the nest is in or hard against the building: under a floor, in a cavity, under a conservatory base or a doorstep. The winged ants have emerged and headed for the light, which is a window. That one is worth a visit, because the colony that produced them is already established somewhere it should not be.

Either way, the winged ants themselves are harmless. The garden ant has no sting at all, and its jaws are not strong enough to do anything to you. They are a nuisance for an afternoon and nothing more.

What to do on the day

Outdoors: close the windows if they are near the house, bring the washing in, and wait it out. It is over in hours.

Indoors: a vacuum cleaner is the quickest answer for the ones in the room, and the important thing is to note where they came out: which room, which corner, what gap. That is the single most useful piece of information for finding the nest afterwards, and it is gone by the next day.

What not to do is spray, for all the reasons in the article on that. Killing the winged ants changes nothing about the colony that made them.

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