Why Bats Are Worth Waiting For

Stand at the end of a warm June evening, with the light draining from the sky, and you may catch a flicker of something small and fast turning above the hedge. That hurried, jerky flight is almost certainly a pipistrelle — the most common bat in Britain and a creature that can put away several thousand midges and small moths in a single night. There are eighteen species of bat resident in the UK, from the tiny soprano pipistrelle to the noctule, which flies high and fast over the treetops.

All of them are protected by law. It is an offence to injure, kill or disturb a bat, or to damage or obstruct a place they use for shelter, whether or not a bat is present. That protection is worth remembering, because the most helpful thing a gardener can do is often the least intrusive: make the garden richer in insects, darker at night, and better connected to the trees and hedges around it. Do that, and bats will find you.

The Three Things a Bat Needs

Strip away the romance and a bat's requirements are refreshingly simple. Every species in the UK needs the same three things within reach of one another:

• Food — insects, in quantity, from spring through to autumn.
• Dark corridors — sheltered, unlit routes between roosts and feeding grounds.
• Safe roosts — crevices and cavities where they can sleep, breed and hibernate undisturbed.

Most gardens already offer a little of each. The trick is to join them up, so a bat can move from a roost in a neighbouring roof, along a hedgerow, to a pond full of midges, without crossing a floodlit lawn or a bare, open gap.

Plant for Insects After Dark

Bats hunt by echolocation, but the insects they eat are often drawn to flowers by scent rather than sight. Planting things that release their fragrance in the evening — especially pale ones that glow in low light — turns a border into a feeding station.

• Night-scented stock, evening primrose and sweet rocket for scent after dusk.
• Honeysuckle and jasmine, which moths and small flies visit late into the night.
• Lavender, marjoram, catmint and ice plant (sedum), all rich in nectar and easy in a sunny spot.
• Knapweed, ox-eye daisy, red valerian and devil's-bit scabious for a longer season of flowers.

Leave a little untidiness too. A patch of long grass, some nettles in a corner, log piles and leaf litter all raise the number of moths, beetles and midges in the garden. Avoid insecticides entirely if you can, and let the garden's own predators do the work.

Keep the Night Dark

Light is the quietest killer of bat activity in a garden. Most British bats will avoid a brightly lit area, and a single security light left on all night can sever a commuting route used for decades. If you need outdoor lighting, a few simple choices make a large difference:

• Use a warm amber or warm-white bulb rather than a harsh blue-white one.
• Fit a hood or shield so the light points downwards at the path or step, not up into the sky or across the hedge.
• Put lights on a motion sensor or short timer so the dark comes back quickly.
• Leave a dark strip along the boundary, ideally connecting to nearby trees or hedge.

Garden centres rarely label lights by their effect on wildlife, so it helps to think about direction rather than wattage. A light you cannot see from the far end of the garden is one a bat can probably live with.

Water, Hedges and Routes Through

A pond — even a small one, with gently sloping edges and no fish — is one of the best investments a wildlife gardener can make. It draws in insects and offers drinking water on the wing; Daubenton's bat, in particular, skims low over open water to take insects from the surface.

Hedges and tree lines matter just as much. Bats follow linear features to navigate, so a mixed native hedge of hawthorn, blackthorn, hazel and field maple acts as a covered walkway between gardens. If a fence blocks the way, cut a gap of around fifteen centimetres at the base — enough for a hedgehog too, and for a bat's flight line. Mature trees, especially those with hollows, loose bark or a thick coat of ivy, are roosting gold dust; leave them standing if it is safe to do so.

Roost Boxes and Careful Watching

If your garden is already rich in insects and reasonably dark, a bat box is worth trying, though patience is required — it may take a year or two to be occupied. Mount it four to five metres up on a south or south-west facing wall, sheltered from wind and with a clear flight path in. Crevice-loving species such as pipistrelles prefer narrow, snug boxes, while brown long-eared bats like something roomier. Two or three boxes of different designs improve your chances, and a box in use should never be opened.

The best way to enjoy bats is simply to be still. Sit out from about half an hour before sunset on a mild evening between May and September, and watch the sky rather than any box. Note the time, the direction and the height of the bats you see — a steady trickle leaving one spot at dusk suggests a roost nearby. If you want to go further, a simple heterodyne bat detector turns their echolocation into clicks and chirrups you can actually hear, and confirms which species are using your garden.

No garden needs to be perfect. A darker corner, a scented flower, a pond and a gap in the fence will do more for bats than any amount of expensive kit — and you get to spend the evening outdoors, listening.