Educate people to respect them
Bats' survival depends on us. Prejudice and persecution too often result in people killing them. It's by disseminating correct information about their biology, by letting people know how harmless, useful, how highly threatened and thus protected by the law they are, that we can make a difference.
Protect their preferred habitats
Bats need rivers, woodland, wetlands, hedgerows, fields and grassland to hunt their key prey. They also need old hollow trees, buildings, caves and mines to find shelter and breed. To protect them is to protect the natural spaces they exploit and make sure we are not damaging them. The bat species that usually roost inside buildings are likely to become the victims of human intolerance and/or to be exposed to the toxic preservatives used to treat the structural elements made of wood.
In case you need wood treatment against insects, you should consider using short-term effect products that are atoxic for mammals. Although permethrin and other synthetic pyrethroids are largely used (for instance permethrin is also used for Mosquito disinfestation), recent studies showed that in laboratory experiments this substance reduces the reproductive capacity of laboratory animals and provokes foetus anomalies. Instead there are no contraindications for the use of boron salts as wood preservatives against fungi and insects.
Enrich your garden with habitats suitable for bats
For example by planting a mixture of flowers, shrubs and trees that can attract many insects from spring to autumn. You should prefer native plants instead of exotics or hybrids, because they can attract so many more insects.
Put up a bat box
The important thing is to choose the proper design according to the kind of environment. This modelhttp://www.msn.unifi.it/upload/sub/specola/img/batbox_schema.jpg fits urban and suburban environments. You may place the bat box on the wall of a building, for example right under the rain gutters, or on a pole, at least 4 metres high above the ground. It should be mounted under the eaves with six hours of sun exposure if you live in a region where average July temperature is 35°C, and with at least ten hours of sun if the average July temperature is less than 27°C. You can mount your bat box at any time of the year but colonization may require a long time.
The boxes mounted in early spring are more likely to be occupied than in late summer. Anyway, there are no guarantees that a bat house will attract bats even if it meets all proper requirements. Bats must already be in the area, they must find the bat house, and they must like it better than their current roost situation. To find out whether or not your bat house is occupied you can wait for the evening and watch the animals flying out, or you can put a white plastic sheet on the ground right beneath the box an check for guano. Bat boxes usually do not require maintenance but in case you decide to carry out any operation, you should do it in winter, when bats are not there.
Keep your cat indoors!
Cats are the most important predators of bats, and also of many other small vertebrates. They are very skilled and widespread all over our country in large numbers, because they are domestic and thus not subjected to natural selection as wildlife is. Keeping your cat indoors would save the lives of many bats, songbirds and reptiles allowing their populations to begin to recover.