If you find you have a bat on or in your property there is nothing you can do to prevent it. ALL species of bats are protected by law as are their breeding sites and roosts. They may be a pest to you but legally there is nothing that can be done.
Regulation 39 of the Conservation (Natural Habitats) Regulations1994 and Section 9 of the Wildlife and Countryside Act 1981 states: “It is an offense for anyone to intentionally kill, injure or handle a bat, to possess a bat (whether dead or alive), disturb a roosting bat, or sell or offer a bat for sale without a licence. It is also an offence to damage, destroy or obstruct access to any place used by bats for shelter, whether they are present or not.”