When is flying ant day? Why the insects can swarm at any time during summer and what it means
Sunshine, hay fever and Wimbledon, there are few things that signify a British summer more – except perhaps flying ant day.
Commonly known as flying ant day, even though it normally takes place over several days, the peak can be at different times in different parts of the country.
Here’s everything you need to know.
When is flying ant day?
Well, this name is sort of misleading – it isn’t really a set day.
The Royal Society of Biology (RSB) says: “Flying ants often seem to appear on the same day in different locations in the UK – flying ant day. Most ant colonies start with a flying ant – when young queens leave the nest to found their own colony.
“However, our citizen science project, the Flying Ant Survey, has found that there is not actually one day where these ants all appear all at once, but that, depending on weather conditions, the ants can start emerging and flying at almost any point during the summer months, and won’t all necessarily appear only on one day either.
“Really, it depends on the conditions, and ants emerge when wind speeds are less than 6.3 metres per second and temperatures are above 13°C, which can happen several times in the summer.”
But the most likely time for flying ants to emerge is in July or August when there is often hot and humid weather.
Professor Adam Hart from the University of Gloucestershire ran the three-year study from 2012 in partnership with the RSB.
The RSB adds: “One of the primary findings from the survey was that there is certainly not only one flying ant day; the frequency in which the flying ants appear changes each year and is dependent on the weather.
“Colonies also don’t exhibit any significant geographical co-ordination when it comes to taking to the skies; one garden may see flying ants on one day, with neighbours seeing them weeks or even months later.
“During the course of the study, every day in the UK summer that had a mean temperature above 25°C had ants flying somewhere.”
Is there no way to tell?
There is certainly some evidence when they’re coming. A swarm of flying ants a mile long was caught on a weather radar on the south coast on Friday (7 July), according to the Met Office.
The swarms appear on the radars and look similar to rainfall, but the Met Office can check their weather gauges to confirm if it is rain or flying ants.
Simon Partridge, a forecaster for the Met Office, said: “Every year around this time we do pick them up on the rain radar. At the moment it’s harder to tell because we’ve got so many showers and the ants look like showers.
“When we do get the rain, they don’t fly as much.
“It’s generally the southern parts of the UK where we tend to notice it most.
“We haven’t seen any swarms today but it doesn’t mean they’re not there as there are so many showers around.
“They were picked up on the radar on Friday. It was much drier and it was easier to spot them.
“They can be seen several miles across – they look like very heavy showers. On Friday it was about a mile.
“They’re an interesting phenomenon and it’s always this time of year and usually over about a week or so.”
The Met Office picked up the ants on a rain radar on Friday as people took to social media reporting sightings saying it was “flying ant day”.
Meanwhile, pest controllers Merlin Environmental analysed search data to look at when people are Googling for information on flying ants.
Assuming that most people might be doing this because they have seen them, they anticipate the peak of flying ant season to be in July.
They say: “To drill down further we’ve identified the specific week of each year with the most flying ant activity, based on the search data. The table shows the week of each year where UK searches peaked to their highest point between 2017 and 2021.
“Since all spikes over the past 5 years were in July, we can estimate that ‘flying ant month 2022’ will be in July too, but since the highest point of each peak has been a different week each year, it’s not possible to predict which week in 2022 will be the peak for flying ants.”
Why does flying ant day happen?
The ants leave their underground nests to mate and begin new colonies.
Ant colonies start with a female flying ant that will have left their previous colony to begin a new one.
Mating takes place during flight, and the males will die shortly after.
The fertilised female then lands, chews off her wings, then goes about creating a new colony and producing offspring.
Flying ants are not harmful, so if some emerge in your garden it’s best to leave them alone, and they will disappear after a few hours.
How to deal with flying ants
Common sense prevails with flying ants – experts tend to advise you just keep your windows shut or insect screens up.
According to the Royal Society of Biology, flying ants are not dangerous, although they can sometimes bite.
