Pipistrelle bats are the most common of our native bats here in the UK, they are in abundance in the countryside, flying over water courses and resting in barns and garages. But as they grow older the roosts become overcrowded and the young start to look for a new home.
When a bat finds a home it will remain there for the rest of it's life if all is well with the environment around the roost, so if you put a bat box up and get a new young bat to make a roost, then you can look forward to hours of entertainment looking up at the clear night sky at dusk and seeing the bats going around the house and their territory over and over again. We have four bat boxes and three of them are occupied, the fourth faces East and so we can gather they prefer South and West facing. We will see what happens with the East facing box this year (third year) and if nothing occupies it then we will turn it to face West (ish)
The height of a bat box is a little higher than a bird box - 4 to 5 meters if you can get it, so you can mount them on your house eaves or up a tall tree, the best location being near by a water supply, pond, stream, river etc. Our nearest water is about 50 meters away so it does not have to be very close, but the closer the better.
There is no need to feed bats, or even to look after them, in fact, once they have occupied a bat box, then leave them alone, the only way we know our boxes are occupied is by the discolouration on the entrance ramp, also I mistakenly mounted one of the boxes above the bathroom window and so they leave us little messages on the windowsill, but it is not a big mess so they are welcome to stay where they are now. It is illegal to open a bat box unless you are qualified to do so.
Head & body length: 35mm - 45mm
Forearm length: 30mm - 35mm
Weight: 3g - 8g
Colour: Medium to dark brown. Face and around the eyes usually dark
Diet: Mainly small flies and flying insects, particularly midges and mosquitos over water.
During the summer, females form maternity colonies where they give birth to a single young in June or early July. For three or four weeks the young are fed solely on their mother’s milk. After about four weeks the young are able to fly and at six weeks they are able to forage for themselves. Then they will either stay with the mother in her colony, or if it is overcrowded, they will find a new home close by.