A BIRD box in a Bradford garden has become home to an unusual swarm of bees - known as tree bumblebees.

The species, which can be smaller than other bees more commonly found in this country, were not spotted in the UK until 2001.

Brian Wilkins, 83, of Hammond Square, Heaton, spotted more than 100 of the small bees in his garden at the weekend.

He said: "They have only been in the country for the last ten years and are smaller than the common bumblebee.

"I first discovered them last week but they are creating a very big swarm now."

"One of my neighbours belongs to the Beekeepers' Association so is going to report the swarm for me. I daren’t disturb them, but hopefully someone will then come and remove them."

Advice from the Bumblebee Conservation Trust warns that this type of bee can show strongly defensive behaviour and if dealing with the species, not to put members of the public in danger.

Queens, workers and males all have a black head, brown-ginger thorax, black abdomen with a white tail. It prefers to nest above ground, often inhabiting bird boxes.