Where to Position a Bat Box in your Garden

Put a bat box at least four metres above the ground, on a building or a pole rather than a tree, facing somewhere between south and south-east, with a clear flight path in and nothing shining on it at night. Get those four things right and you have done most of what you can do. Everything else is patience.

Bats are slow to find a new box. It is entirely normal for one to sit empty for a couple of years before anything moves in, which is why the siting is worth getting right first time rather than moving it about.

• The siting rules
• Why height and aspect matter
• Which box, and for which season
• The three bats most likely to visit
• Making the garden worth visiting
• The law
• Frequently asked questions

The siting rules

• Height: four metres or more. Higher is better, and below three metres is rarely used.
• What to fix it to: a wall, gable end or a purpose-set pole. Buildings and poles keep the box away from the branches cats and other predators use to reach it.
• Aspect: south to south-east, so the box warms through the morning. Bats need warmth to raise young.
• Approach: a clear, uncluttered flight line in. Bats drop out of the entrance and need space beneath, so avoid mounting directly above a shed roof, a hedge or a fence.
• Light: away from security lights, porch lights and street lights. Artificial light at a roost entrance will stop bats using it.
• Shelter: out of the prevailing wind, which in most of the UK means not on a west-facing elevation.

If you have room, put up more than one box facing slightly different directions. Bats move between roosts as the weather changes, and a choice of temperatures is more useful to them than one perfectly placed box.

Why height and aspect matter

Height is about safety and approach. Bats emerge by dropping from the entrance and gaining height as they fly, so a low box gives them nowhere to go and puts them within reach of cats. Four metres is the working minimum for both reasons.

Aspect is about temperature. A maternity roost needs to stay warm enough for the young to develop, and a box that catches the morning sun does that without cooking in the afternoon. In winter the opposite is true, and hibernating bats want stability rather than warmth, which is why a deeper, multi-chamber box in a sheltered, shaded spot suits the colder months.

The reason to avoid trees is more prosaic than it sounds. Branches give predators a route to the box, foliage obstructs the flight line, and trees move in the wind. A wall does none of those things.

Which box, and for which season

Natural roosts are disappearing as old trees come down and roof spaces are sealed up, which is the whole argument for putting boxes up at all.

• Single chamber. A narrow roosting space, used occasionally through the warmer months as a rest stop between foraging flights. The simplest box, and the easiest place to start.
• Two or three chambers. The most useful all-round design. Several internal spaces mean several microclimates, so bats can move between them as conditions change, and there is room for a small group to cluster. This is the type to choose for a maternity colony.
• Deep crevice and larger multi-chamber designs. Built for hibernation, with the thermal mass to hold a stable temperature. These want a shaded, sheltered position out of the wind rather than a sunny one.

The WildYard boxes we stock are FSC-certified timber with grooved interiors, which bats need in order to grip and climb inside. A smooth-walled box is no use to them, and it is the detail cheap boxes most often get wrong. They sit in Birds & Wildlife.

The three bats most likely to visit

Eighteen bat species have been recorded in the UK. Three turn up in gardens far more than the rest.

Common pipistrelle

Tiny, at around 5g, and the one you are most likely to see darting about at dusk along a hedge line or over a lawn. Roosts in crevices, in buildings and in bat boxes, which makes it the species most likely to take up residence.

Soprano pipistrelle

Very similar, but favours wetter habitats and feeds heavily on midges and mosquitoes. If you have a pond, this is the one to hope for. Uses multi-chamber boxes and roof tiles.

Brown long-eared bat

Unmistakable ears and a slow, fluttering flight. Feeds on moths and beetles, often picking them straight off foliage rather than catching them in the air. Roosts in lofts, barns and deep crevice boxes.

Each has different preferences, which is the practical argument for putting up more than one style of box if you have the walls for it.

Making the garden worth visiting

A box is only worth putting up if there is something to eat nearby. All UK bats feed exclusively on insects, and a single common pipistrelle can take a few thousand small insects in a night, so the garden needs to produce them.

• Plant for night-flying insects. Jasmine, honeysuckle and evening primrose all release scent after dark and pull in moths.
• Stop using pesticides. They remove the food supply, and bats accumulate what their prey has been exposed to.
• Add water. A pond generates insects and gives bats somewhere to drink on the wing.
• Keep hedges and trees. Bats navigate along linear features, so a hedge is a flight corridor rather than just a boundary.
• Turn the outside lights off. Lighting disrupts feeding and navigation, and it is the easiest of all these to fix.

Bats are a good indicator of how a garden is doing more generally. They sit near the top of an insect food chain, so a garden that supports them is almost certainly supporting a great deal else.

The law

All UK bat species and their roosts are protected under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017. It is an offence to disturb bats or damage a roost without a licence, and a roost is protected whether or not bats are in it at the time.

In practice that means you may put a box up freely, but you must not open it, inspect it or handle its occupants. If you are planning building work and suspect bats are present, stop and take advice before going further. The Bat Conservation Trust runs a helpline for exactly this.

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Frequently asked questions

How high should a bat box be?

At least four metres above ground level, and higher if you can manage it safely. Height matters for two reasons. Bats leave a roost by dropping from the entrance and gaining height as they fly, so a low box gives them no room to get away. And a box within reach of the ground, or of a branch, is a box a cat can get to. Below three metres, boxes are very rarely occupied, so it is not worth compromising on this.

Which way should a bat box face?

Somewhere between south and south-east for a summer or maternity box, so that it warms through the morning sun without overheating later in the day. Warmth matters because young bats develop faster in a warm roost. Hibernation boxes are the exception and want a shaded, sheltered position where the temperature stays stable rather than climbing. If you have space for more than one box, face them in slightly different directions and let the bats choose according to the weather.

Can you put a bat box on a tree?

You can, but a wall or a pole is better. Branches give cats and other predators a route to the box, foliage gets in the way of the flight path bats need in and out, and a tree moves in the wind while a building does not. If a tree is your only option, choose one with a clear approach, fix the box on a trunk well clear of side branches, and expect a lower chance of occupation than the same box on a gable end.

When should you put up a bat box?

Any time of year, though late winter and early spring are ideal because it gives bats the chance to find the box before the breeding season. Do not expect quick results. Bats are slow to adopt a new roost and a box commonly stands empty for one or two years before anything uses it, which is why the position is worth getting right at the outset rather than moving it about. Putting up two or three boxes in different aspects improves the odds considerably.

Can you open a bat box to see if bats are using it?

No. All UK bat species and their roosts are protected under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2017, and it is an offence to disturb bats or their roosts without a licence. That protection applies to the roost whether or not bats are in it at the time. Watch from a distance at dusk instead, when you may see them emerge, and look for droppings beneath the box. If building work might affect a roost, take advice before starting.