Bats are declining and need your help. A few years ago the mouse-eared bat became extinct in Britain, which is the first time that a mammal has become extinct in Britain since the wolf.
There are many myths concerning bats but the truth is they are fascinating creatures that are harmless and cause no damage. They benefit people by eating insects – a single pipistrelle, the smallest bat in the UK, weighing in at 4 grams, the same as 10 paperclips, can eat 3,000 insects per night.
Is there a threat to bats?
Bats are classed as an endangered species and as such, are afforded great protection. Bats and their roosts are fully protected by the Wildlife and Countryside Act 1981. It is an offence to intentionally kill, injure or take a bat, or to be in possession of a live or dead bat. The fine for an offence is up to £5000 per bat. It is also an offence to disturb bats or to damage, destroy or obstruct a bat roost, even if bats are not present at the time.
What you need to know to protect bats
Bat droppings make good fertiliser. They are high in nitrogen, phosphorus and potassium. Also makes good non-corrosive insulator in loft.
Pollarded willows make good bat roosts.
If you find an injured or stunned bat on ground in high summer it will probably be a young animal. Hang them up as near to roost site as possible and at dusk when mother emerges she will react to baby’s call and gather it up.
Winter roosts are declining. If you have suitable roof or loft space make sure there is an entrance hole. They can get through 1.5cm gap. Or you could fix boarding to a wall at 20mm battens. Under the eaves is best for shelter. They need stable temperatures in winter with some sun but not too much.
Bat boxes are another alternative. Bats gain access at the bottom of the box. Size and shape are not critical but front to back shouldn’t exceed 10cm as they prefer constricted spaces. Use roughly sawn and untreated planking 25mm thick which you should roughen further on inside and outside with shallow horizontal sawcuts. Entrance slit should be 15-20mm wide and at least 50mm long or full width of box.
Sites facing south used spring and summer and facing north used winter and autumn. Height above ground not critical but must be clear flight path to box and it should be out of prevailing winds. A box could house up to 50 bats. You can tell if it is used by blackish brown droppings. If not used in 3 years re-site it.
You should take action if you suspect the law has been broken or is going to be broken, for example if:
- A bat or bats have been killed
- A bat roost has been blocked or is going to be blocked
- A building that has roosting bats is going to be renovated or demolished, (for example, look for scaffolding going up) or chemical treatment for woodworm or damp. You will need evidence that bats roost there, watch at dusk to see if bats emerge or at dawn to see if bats return. Presence of droppings (like mouse dropping but crumbling to powder) also indicates a roost.
- A tree with a bat roost is going to be felled or have branches removed. A stain below a hole in the tree is a sign that it might be used by bats, but many trees used by bats show no obvious signs.
Your local bat group should be informed about any bat roosts that you know of, so that they can be better protected.
What you can do
- If you suspect the law has been or is being broken, contact the police and ask for your local police Wildlife Liaison Officer.
- You should also contact your local bat group to inform them of the problem – their details are available from the Bat Conservation Trust at www.bats.org.uk The Bat Helpine is 0845 1300 228.

Reproduced with permission of North West Parks Friends Forum