Oh, and your bats won't be eating fruit. Fruit bats are big, fly in daylight, and are not found in the wild n Britain. Yours are probably pipistrelles; if you are lucky (?) one or two will fly into the house; we used to have to rescue some found, oddly, on the carpets, in another house, and in the current house we once found some roosting in a wardrobe (what did I say about clothes moths [above] ? !) in a back, guest, bedroom which we never used but which had a window open. Our species al live on insects.