Building a Hedgehog House for Frosty Nights

Why hedgehogs need a helping hand before the frost

Hedgehogs are one of Britain’s most beloved garden visitors, but their numbers have dropped sharply in recent decades. As autumn turns to winter, each hedgehog must find a dry, sheltered spot to hibernate — a hibernaculum — where it can sleep through the coldest months without freezing or waking too often. A single frosty night can be fatal for an underweight or exposed animal. By building a simple hedgehog house, you give one a fighting chance. It is a small project with a big payoff: a quiet corner of your garden becomes a safe winter den.

Hedgehogs usually begin hibernating in November, though mild weather can delay it until December or even January. They wake occasionally, especially during milder spells, and may move to a different nest. A well-made house mimics the natural hollows under hedgerows and log piles that are increasingly hard to find. Untreated wood, dry leaves and a sheltered position are the key ingredients.

Choose a quiet, sheltered corner

Placement matters as much as the house itself. Hedgehogs are shy and will abandon a den that feels exposed or is regularly disturbed. Look for a quiet corner that stays dry and shaded for most of the day — under a dense hedge, behind a shed, or beside a compost heap. The entrance should face away from the prevailing south-westerly winds, so an east or north-east aspect is ideal. This keeps rain and cold draughts out of the sleeping chamber.

• Avoid direct sun: a house that bakes in summer or stays damp in winter will not be used.
• Keep it away from badger runs and busy paths: badgers can tear houses apart, and foot traffic causes stress.
• Raise it slightly: sit the house on two bricks or a piece of slate to stop damp rising from the ground.
• Leave a wild patch nearby: a pile of leaves and twigs gives hedgehogs an alternative nesting spot.

Build a dry, draught-free den

You can buy a hedgehog house, but making one is cheaper and more satisfying. Use untreated wood — pine, plywood or scrap timber without paint, varnish or wood preservative. Treated timber can contain chemicals that harm hedgehogs. The design should be simple: a box roughly 40cm long, 30cm wide and 25cm high, with a sloped roof that overhangs the sides. A removable roof makes spring cleaning easy.

The entrance is crucial. Create a tunnel about 15cm long and 13cm square that leads into the main chamber. This stops cats, foxes and badgers from reaching inside, while still letting hedgehogs through. Fix the tunnel firmly to the box and ensure there are no sharp edges or protruding nails. Drill a few 5mm ventilation holes near the top of the sides to prevent condensation, but keep them small so rain cannot enter. Cover the roof with roofing felt or damp-proof membrane, and make sure it overhangs the entrance by at least 5cm.

• Floor: solid wood, not wire mesh, which can injure feet.
• Fixing: use galvanised screws rather than nails for a tight, safe join.
• Roof: hinged or removable, with a waterproof covering.
• Interior: a single chamber, no dividers, so the hedgehog can curl up in a tight ball.

Line the den with dry leaves, not hay

Hedgehogs build their own nests from leaves, moss and grass. Give them a head start by half-filling the chamber with dry autumn leaves — oak, beech and hawthorn are excellent. Avoid hay, which holds moisture and grows mould, and skip straw unless it is thoroughly dry and mixed with leaves. A handful of leaves at the entrance helps the house blend in and signals that it is a safe place to investigate.

Do not add food inside the house. It attracts rats and mice, and uneaten food quickly goes mouldy. If a hedgehog wakes during a mild spell, it will forage outside. You can leave a shallow dish of fresh water nearby, but only if it will not freeze solid. In freezing weather, a hedgehog that wakes may struggle to find water, so a dish placed in a sheltered spot can be a lifeline.

Leave hibernating hedgehogs undisturbed

Once a hedgehog moves in, resist the urge to check on it. Disturbing a hibernating animal uses up its precious fat reserves and may cause it to wake and wander into the cold. From November to March, treat the house as off-limits. If you accidentally uncover a hedgehog, cover it back with leaves and leave the area quietly.

In spring, usually April, check whether the house is empty. If it is, clean it out, replace the leaves and make any repairs. If a hedgehog is still inside, leave it alone until it moves on. A hedgehog seen out in daylight during winter is in trouble — it may be ill, injured or underweight. Do not try to keep it warm yourself; contact a local wildlife rescue for advice. With a little effort now, your garden can offer one small, spiky creature a safe place to sleep until the warmer days return.