Despite their sometimes "scary" image, in reality bats are a friend not only to gardeners but, people in general. A single pipistrelle bat can eat up to 3000 insects per night. Many of these insects will be nuisances like mosquitoes and gnats, and of course many will be feeding on your plants. Bats fly and feed by night, so a plentiful supply of night flying insects is essential. Many herbs and flowers attract insects, and those that give off scent by night are particularly important to bats because it is these that will attract the insects. Amongst the common ones recommended plants are honeysuckle, evening primrose, night scented stock, lemon balm, mint, borage, nicotiana, sweet rocket (every garden should have some anyway), white jasmine and dogrose.