ONCE a year, seagulls gorge on clouds of flying ants and behave like drunkards.

Gulls are seen tottering on the wing, bashing into cars and becoming roadkill as they feats on the insects, which surface like clockwork at this time of year in a mass mating ritual.

The annual emergence of the ants, which has just happened, has become known as “flying ant day”.

Hot on its heels in Brighton is the biggest day in the seagull calendar: a boozy bug bonanza. One popular explanation for the birds’ strange behaviour is they are addled by acid in the ants’ bodies.

But a wildlife expert has poured cold water on those rumours.

Sussex Wildlife Trust conservation officer Charlotte Owen said this was a common misconception.

She said: “We get loads of reports of seagulls acting drunk and disorderly around this time of year.

“They’re not drunk in the conventional sense – but they certainly act like it. They’re making the most of the moment when the ants’ new queens and males fly up to mate on the wing.

“To an extent there is safety in numbers for the ants: but they provide easy pickings for the birds.

“The seagulls are seen out in force, pecking at the crawling ants and snapping at them in mid-air. They’re obviously having a field day.

“What people assume is that the formic acid in the ants is affecting the seagulls. It’s a common assumption, but in fact there’s no scientific consensus.

“There might be a case if we were talking about another species, like wood ants, which contain higher concentrations of formic acid and actually spray it out of their abdomens in self-defence.

“But the flying species we see around this time every year in the UK – black garden ants – don’t contain a lot of formic acid. Even though the gulls are eating a lot of them, it’s unlikely to have much of an effect.

“It’s much more likely the gulls are behaving oddly because they’re focused on chasing the flying ants everywhere, and not paying attention to things like traffic. They’re also being becoming sluggish as they gorge on such a massive feast.”

That said, seagulls have been known to enjoy a drink. Last year, the RSPCA took in several gulls “stinking of alcohol”. Workers at the charity said the birds struggled to stand, but seemed to recover after vomiting.