There are 17 species of bat to be found in Britain. Bats are often found in gardens and some, such as Pipistrelles and Long Eared Bats, may also roost in buildings. If you are lucky enough to have bats in your property then you will generally see them at dusk from March when they emerge from hibernation right through to October. They are perfectly harmless and are protected by law so they should never be disturbed.
Bats feed upon insects such as midges, mosquitoes, moths and beetles. In fact a single Pipistrelle bat can eat up to 3000 midges in a night, so a ready supply of insects is essential for encouraging bats to your garden.
The best way to achieve a good insect population is to grow a large range of nectar rich plants in your garden that will produce flowers from early spring through to late autumn. Use a mix of trees, flowering shrubs, vegetables and perennials with different flower shapes.
Native plants will entice a better diversity of insects so try to incorporate some into your planting schemes. Use native plants such as Bluebell, Honeysuckle, Hawthorn, Rowan and Ivy. Non natives such as Echinacea, Sedum, and Buddleja are also useful pollen rich plants.
Ponds are a magnet for wildlife on gardens. Bats enjoy whizzing across ponds and boggy areas while feeding on midges that hover over water on summer evenings. A pond will also provide a water source for bats and other wildlife to drink from.
The edges of wildlife ponds can be planted with marginal plants that will provide cover and breeding sites for insects. Avoid adding Goldfish to wildlife ponds as they eat insect larvae and thereby reduce the food source for your winged visitors.
Building a compost heap will also encourage a better biodiversity of insects in your garden and therefore provide a better diet for bats in the area. An undisturbed log pile in a shaded area will have a similar effect.
It is important to avoid using chemicals such as herbicides and insecticides as this will reduce the food source for visiting bats.
Bat boxes provide a roosting site for bats. They can be bought commercially or made from untreated, rough sawn timber. Leave an entrance gap at the bottom of just 15-20mm wide.
Position bat boxes at least 4 or 5 metres above ground, preferably close to hedges and tree lines that bats have been spotted flying along. If a bat box is to be installed on a building then place it as close to the eaves as possible. Choose sheltered positions that are exposed to sunlight for at least part of the day, and protected from strong winds.
If you have a suitable location for a bat box then its well worth installing several in the same area. Position them so that they each face a different direction to provide a range of temperatures. This will give bats the opportunity to change roosts according to the seasonal conditions. Bear in mind that once in place it is illegal to open them without a licence.