Staff at a Yeadon financial firm are being driven batty after discovering they have some unusual lodgers.

When workers at Manor Financial Services started having to duck because of the number of bats that were flying through their offices they decided that it was time to call in the experts.

What they discovered was a colony of Soprano Pipistrelle bats living just feet above their heads in the roof space of the company's fourth floor office.

But now the workers are going to have to get used to their new lodgers - who are heavily protected by law and could roost in the building until late August, bringing up their young.

Company chairman Keith Madeley said although it had come as a shock at first staff were now quite excited about having bats in their belfry.

He said: "We had one flying around the office a few weeks ago but we thought it was a one-off and it flew out of the window.

"Then we had another one on Friday and at the weekend the cleaner found a couple in my son's office.

"That's when we thought we'd better call the experts in."

When investigators from the West Yorkshire Bat group arrived they discovered a colony of up to 200 Pipistrelles living behind the concrete slabs on the face of the building. Somehow the cheeky mammals have worked their way into the building and under the fifth floor floorboards.

Mr Madeley said: "We're getting used to them now.

"They're lovely little things and actually quite cute. Apparently they eat about 3,000 midges every night so they're doing us a favour.

"We'd noticed there weren't many flies about!"

Diane Gregory, secretary of the West Yorkshire Bat Group, said the Pipistrelles will probably move out of their roost once their young were ready to face the outside world.

She said: "It's actually illegal to move them on.

"You're not allowed to block up an entrance to a building because you could trap the adults and their babies inside where they all rot - which would be very unpleasant.

"There are massive fines for killing a bat, it can be up to £5,000 per bat and even a prison sentence, so if anyone discovers they do have them they should contact the authorities.

"This one's a maternal colony so they will probably disperse later this year but they may come back."

Once the roosting season is over in September the company could apply to government body English nature to have the entrance to the bat-lodgings sealed.