Flying Ant Day: the science behind the summer swarms

http://www.theguardian.com/environment/shortcuts/2015/aug/03/flying-ant-day-summer-swarms

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Did a swarm of frisky flying insects put a dampener on your weekend barbecue? Well, there’s a good reason – for a brief period each summer, millions of flying ants appear in Britain for a short frenzy of mid-air mating. This year, what’s known as Flying Ant Day fell on Sunday and colonies were spotted erupting out of pavements, spilling into gardens, bedrooms, on to sofas and even riding the London Underground.

Flying Ant Day is actually a bit of a misnomer, says Professor Adam Hart of the University of Gloucestershire. A flying ant survey he has run with the Royal Society of Biology since 2012 has found that the idea of one synchronised 24-hour period of emergence is a myth. Sometimes they come out over a few days, or even weeks.

How do the ants know it’s time to emerge? The weather, mainly. “As it gets towards June, the colony starts producing flying ants, [which are] these reproductive males and females,” explains Hart. “The females will start a new colony and when it’s warm they emerge en masse. They fly into the air and the males mate with the females. The females drop to the ground, lose their wings and, if they survive the birds, start a new nest.”

If they come out together in their thousands they have a greater chance of survival. “You’re flooding the predators,” explains Hart. “No matter how many seagulls are up there, they can’t get them all.”

While the queen ant can live for four to five years, the male ant dies quite soon after it emerges, its genitals exploding.

Though descriptions can be overblown, Flying Ant Day isn’t without its casualties. A Dorchester cricket team in 2006 blamed flying ants for its relegation after a distracting tea-time emergence.

Our flying ants may be annoying, but they’re crucial to the environment. “Ants are very important. They recycle nutrients and aerate the soil and provide lots of food for birds,” says Hart. Not so gross after all.