LONDON —  They. Are. Everywhere.

They crawl around underground waiting until the time is right. Once ready, they emerge from their colonies, crawling out from cracks and holes in the ground, looking for mates. For flying ants, embarking on nuptial flight means it's time to reproduce. For Brits, it's time to swat, shut the windows and shudder.

Yes, while Americans were celebrating Independence Day on Wednesday, Brits were battling billions of winged insects that have fled the nest in an attempt to reproduce.

"Flying Ant Day” is a fascinating yet highly irritable occasion that is one of the most dreaded in the British calendar year. Within minutes of the first sighting, social media users joined forces to warn their fellow Brits of the impending doom. "They're everywhere!" exclaimed one Twitter user. "One landed in my mouth" wrote another.

“It's too late for me, save yourselves” declared one clearly defeated individual. Naturally, #FlyingAntDay began trending in Britain on Twitter as users shared horror stories, photos and video footage of the sudden, but rather familiar infestation.

At Wimbledon, tennis players also came under attack. Australia's Caroline Wozniacki urged officials to take action as the insects swarmed the court.

“Is there a spray? I want to be here to focus on tennis, not eating bugs,” she said.

“We already knew the biology of it; they're basically doing it to have sex,” said Adam Hart, a University of Gloucestershire professor who is also a Royal Entomological Society fellow.

In short, here's how to get intimate like an ant: Be a queen. Fly into the sky. Mate with different colonies. Drop back to the ground. Try not to get eaten by birds. Side note: The luckiest of ants are able to dodge death by shedding their wings and digging holes in the ground before going back into hiding to start a new colony.

And they say romance is dead.

Despite being labeled “Flying Ant Day” and often overdramatized British media — there are even reports of birds getting “drunk” on the winged insects — the emergence of ants can actually last longer than 24 hours. Hart explains that warm weather can trigger the ants to emerge at different times.

“It really depends on the weather. There's not a single day, but there are some days where the ants are a lot more active than others,” Hart said. “We have this idea of Flying Ant Day, but they can fly throughout the summer on multiple days.”

Despite landing on people, taking over gardens and generally being a nuisance, Hart assures that the ants are not at all harmful, but in fact are important to soil fertility, pest control and, of course, as a source of dinner for hungry birds.

“They're really important; we need to have more ants flying around,” though many might be inclined to disagree, said Hart, who worked with a group of colleagues to produce a flying ant survey that explored what was happening with the insects in the summer.

Flying Ant Day doesn't normally coincide with the Fourth of July, though the bugs normally do show up some time during the month. Hart's survey and analysis revealed that temperature and wind speed are key factors when it comes to the emergence of winged ants. "As soon as they get a good day, off they go," he said.  Britain has been enjoying a particularly long spell of warm weather, which probably triggered the ants to emerge from underground earlier than in recent years.

Referring to Wednesday's plague of ants as “the little things that run the world” (just what would Beyoncé think of all this?), Hart promised they would be back.

“We'll see them again through the summer; this won't be the end of flying ants.”