A bat inhabited cottage in the area has led to a £7million flood defence scheme being altered.

The 150-year-old lock keeper's cottage in Lindley Woods is no longer abandoned - in fact it has hundreds of little guests.

To Yorkshire Water's surprise it now plays host to hundreds of Long-eared bats and Pipistrelle bats, which have forced the company to rethink their flood strategy for Otley.

Yorkshire Water has to raise the dam wall at Lindley Wood reservoir in order to protect the area from flooding and the plans involved knocking down the cottage to do this.

A spokesman from Yorkshire Water said: "We are carrying out a massive £7million scheme at Lindley Wood, Fewston and Swinsty reservoirs to raise the crest of the dam wall, it is something we have to do as a statutory body.

"At the end of the dam there is a dam keeper's cottage and in the loft we found lots of bats and we are not allowed to move them.

"At the moment it looks like a building site, you cannot see the bats because it is their mating season and you cannot disturb them."

When inspectors surveyed the house they discovered the bats living in the loft, leaving them with two options, either move them or incorporate the house into the dam.

So now the house will be filled with concrete up to the first floor and become part of the dam and the bats will be able to keep their home-made bat cave.

The spokesman added: "We are going to fill in the first floor of the building with concrete and we are leaving the loft, the building will be incorporated into the super structure. We have got bat experts working with us to collaborate the strategy. We will adopt the house on to the dam wall.

"Had we needed to remove the bats it would have taken far longer. As a solution we are incorporating the building into the structure.

"We regularly have to improve the dam to protect the area from the chance of floods." The project started in June and will take two years to complete.

The Pipistrelle bats weigh between three to eight grams, can live up to 16 years and can have a wing span of up to eight inches.

A mother bat produces one offspring, but they have been known to have twins. The average number in a colony is between 25 to 100, their favourite snacks are midges, mosquitoes and moths.

The Pipistrelle is not an endangered species but there are strict laws protecting them. This is not the first case of bats taking over a local property, last week it was reported that a colony of Soprano Pipistrelle bats were living in the premises of Manor Financial Services in Yeadon.

It is illegal to move bats or to block up an entrance to a building because you could trap the adults and their babies inside. 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.

Once the roosting season is over in September people can apply to English nature to have the entrance to any bat-lodgings sealed.