A huge flock of gulls were seen darkening the sky above Overstrand.

Hundreds of the birds, which were joined by other species including swifts and terns, were seen circling up into the sky above the rooftops and shoreline of the north Norfolk village just before midday on Friday, July 17.

Sophie Barker, Norfolk Ornithologists Association warden, based in Holme-next-the-Sea, said flying ants were the likely cause.

She said: “It’s quite common to get a big, mixed flock of gulls go up in a spiral, and when you get a lot of them you get terns join in as well.

“This is the time of year when we do tend to get a lot of flying ants - they take wing as they reach a certain temperature.

“The birds use thermals and they expend almost no energy as they’re going around, and they’re able to pick off the ants as they go up.”

The behaviour is called the ants’ ‘nuptial flight’.

During the flight, virgin queen ants mate with males and then land to start a new colony.

Have you seen a similar phenomenon? Email your photos and video to stuart.anderson@archant.co.uk