From a distance it looked as if badgers had dug holes and made themselves a home in a mound of builders' earth and concrete.

But workers taking a closer look quickly backed off when they realised the mound was actually swarming with bees.

Thousands are living in the middle of the earth and concrete at the yard of the old Preston Barracks site in Lewes Road, Brighton.

The swarm is relatively isolated but is about 200yds from homes in Saunders Park View which back on to the unit.

R&M Scaffolding started using the yard at the weekend and only realised there was a problem when workers saw bees flying in and out of the mound.

Director Mike Middleton said: "There were big holes in the earth and at first we thought they had been made by badgers or foxes.

"It was only when we got closer that we saw the bees.

"We took one look and then kept well away.

"At the moment they are not bothering us and we are not bothering them but if they become a problem then we are going to have to do something about them.

"We are certainly keeping our distance.

"This site has been empty for a while so they've had quite a lot of time to get established."

Beccy Champion of the Sussex Beekeepers Association said it was the right time of year for bees to swarm.

She said: "They swarm between April and September and generally peak around May and June but you do get the odd stragglers.

"We always advise people to get in contact with a local beekeeper when they come across something like this."