The UK hedgehog population has declined by over a third since the year 2000 and by more than 50% since the 1950s. Habitat fragmentation is one of the primary drivers – hedgehogs need to roam up to 2km per night to find enough food and suitable mates, and a suburban landscape of walled and close-boarded fenced gardens creates a patchwork of isolated green spaces that hedgehogs cannot move between. A single unbroken boundary stops a hedgehog reaching the next garden entirely.

A hedgehog highway – a 13cm x 13cm gap at the base of a fence or wall – costs nothing significant to install and immediately reconnects the garden to the broader landscape. If neighbours on both sides also create gaps, the effect multiplies: instead of being isolated, a garden becomes part of a corridor that hedgehogs can travel through night after night. The Hedgehog Street campaign, run jointly by the British Hedgehog Preservation Society and the People’s Trust for Endangered Species, has registered over 100,000 hedgehog highways across the UK as evidence of what networked garden action can achieve for a declining species. If you want to attract hedgehogs to your garden more broadly, the highway is the essential first step before any other habitat improvement is worth making.

Why hedgehog highways matter

The case for a hedgehog highway comes down to one fundamental fact about hedgehog behaviour: they are wide-ranging animals that cover large territories every night. A single hedgehog may visit twenty or more gardens during a night’s foraging. In a landscape where every garden boundary is solid – close-boarded fences at ground level on all sides – that hedgehog is trapped. It can forage whatever its own garden contains, then has nowhere to go. Gardens that do not connect to their neighbours are ecological dead ends for hedgehogs regardless of how much habitat, food or shelter they contain.

The highway also matters because hedgehog foraging is inherently connected to insect abundance, and insect populations are themselves distributed unevenly across gardens. One garden may have a rich lawn invertebrate population. Another may have excellent slug habitat under leaf litter. A third may have a productive log pile that beetles and earthworms colonise. A hedgehog moving freely between these gardens harvests from all three food sources rather than exhausting any one. Connected gardens effectively function as a shared foraging territory, producing better outcomes for local hedgehog populations than the same area of habitat in isolated fragments.

How to make the hole

The standard hedgehog highway specification is a square hole of 13cm x 13cm – large enough for a hedgehog to pass through comfortably but small enough to exclude cats, foxes and most other animals that you might not want travelling between gardens. In a close-boarded wooden fence, the hole is cut at the base of the fence using a jigsaw. Mark the square with pencil, drill a pilot hole in one corner to start the jigsaw blade, and cut cleanly around the square. Sand any rough edges to prevent injury. The cut section does not need to be retained – simply remove it.

For a close-boarded fence, the jigsaw is the right tool and the job takes around ten minutes. A cordless jigsaw makes this a genuinely quick project – the kind of tool covered in our best cordless jigsaws UK comparison if you need one for other garden projects too. Where a fence panel sits on a gravel board, cutting through the gravel board may be necessary to reach ground level – a jigsaw fitted with a concrete blade handles this. Fix a hedgehog highway sign plate near the hole to indicate to neighbours and visitors that the gap is intentional and to discourage anyone from blocking it.

Where to position it

The most effective position for a hedgehog highway is at ground level in a back corner of the garden – near the base of a hedge or beside an existing gap under a gate or outbuilding. Hedgehogs follow boundaries and edges rather than crossing open ground, so a gap in a corner where two fence lines meet is more likely to be used than one in the middle of an exposed fence panel. Position it where there is some cover nearby on both sides – rough grass, a hedge base, a log pile or a border edge. Hedgehogs are cautious animals and an exposed opening in the middle of a lawn is less attractive than one tucked into cover.

Avoid positioning a highway directly behind a compost heap or directly under a bird feeding station. Both locations are attractive to rats, and while a 13cm gap will not allow rats to enter that could not already get under a fence, placing the highway as a direct route to a food source is not good practice. A pallet compost bin positioned nearby is excellent hedgehog habitat once it is in operation, but the highway entrance itself should open into a clear, safe route rather than directly into a rat attractant.

Getting neighbours on board

A single highway is useful. Two highways connecting three gardens is significantly more useful. A whole street of connected highways creates a genuine wildlife corridor that hedgehogs can navigate across an entire neighbourhood. The practical challenge is agreeing with neighbours to cut holes in shared boundaries – something that understandably requires communication and consent.

The most effective approach is a direct, friendly conversation with a simple explanation of the benefit and the size of the hole. Most people respond positively when they understand the conservation context and the trivially small size of the modification required. Hedgehog Street provides free downloadable posters and letters designed specifically for neighbour outreach – leaving one through a door with a handwritten note is often more effective than a verbal conversation alone. If you have trail camera footage of hedgehogs using your garden, sharing it with neighbours is one of the most persuasive tools available.

Confirming hedgehogs are using it

The simplest monitoring method is a tracking tunnel – a short cardboard or plastic tube placed over the highway entrance with an ink pad on one side and paper on the other. A hedgehog passing through leaves distinctive five-toed footprints. Proprietary tracking tunnels are available from wildlife suppliers, but a homemade version works equally well. Alternatively, a small amount of dry sand or fine soil spread either side of the opening will show hedgehog footprints after a night of use.

A wildlife camera positioned near the entrance provides definitive confirmation and is increasingly affordable – basic motion-triggered cameras designed for garden wildlife are available from around £30-40. Once you have confirmed hedgehogs are using the highway, the next step is to make the garden as productive a foraging stop as possible: rough grass areas, log piles, leaf litter and a shallow water dish at ground level all increase the time hedgehogs spend in the garden and the regularity with which they return. A highway that leads to rich habitat will be used far more consistently than one that opens into a bare, tidy garden with nothing to forage.