A giant swarm of flying ants estimated to be around a mile long has been spotted on the south coast of England.

The Met Office was alerted to the bugs through a rain radar on Friday (July 7) as people took to social media reporting sightings saying it was “flying ant day”.

The swarm, which often looks similar to rainfall on the radar is usually picked up on forecaster's devices at this time of the year over the space of about a week.

The creatures are less likely to fly in the rain and it is harder for the Met Office to tell if it is ants or the rainfall during wet weather, Simon Partridge, a forecaster for the Met Office, said.

He added: “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 [Friday] 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.”

@themediterraneangardener Flying ant day! #learntok #flyingants #insects #planttiktok #garden ♬ Mischievous - Scott Kuehn

What is flying ant day?

Every year it can be quite a shock when you see dozens of large ants with wings crawling around on the floor.

As they take to the air, you might often find yourselves ducking to avoid them landing on you.

The Natural History Museum reports that flying ants are “mature queens and males of the black garden ant”, and they can be up to 15mm long.

It adds: “This annual swarming event usually occurs in July or August and coincides with a period of hot and humid weather. Winged ants appear at different times around the country and local weather conditions are critical for the coordination of swarming activity.

“Ants tend to fly earlier in urban areas than rural areas, probably because temperatures are generally warmer in urban environments, known as the urban heat island effect.”

According to the Royal Society of Biology, there is not always one flying ant day – on as many as 96% of days between June and September, flying ants are spotted.