Hedgehogs can hear a great deal more than we knew

By Earth to Sea News · August 2026

A gentle experiment in Oxford found a hidden range in hedgehog hearing, and with it a kind idea.

Researchers at the University of Oxford have shown for the first time that European hedgehogs hear ultrasound, and they hear a lot of it. The tests found a range running from 4 kHz all the way up to 85 kHz, with hedgehogs most sensitive around 40 kHz. For comparison, our own hearing gives out near 20 kHz, a dog reaches about 45 kHz and a cat about 65 kHz. Twenty rehabilitated hedgehogs took part, tested gently and without harm, checked by a vet and released back to the wild the following night. Nobody had ever measured this before, and it turns out hedgehogs have been listening to a whole layer of the world we cannot hear.

What makes the finding so useful is what it could allow. If hedgehogs can hear a sound we cannot, then cars, robotic mowers and garden strimmers could carry a small emitter that politely asks a hedgehog to move along before the machine arrives, with no noise at all for the neighbours. That is the hope rather than the finished article, and the team is careful about it. They still need to learn which frequencies a hedgehog actually dislikes, whether the animals would simply grow used to the sound, and whether a warning can travel far enough ahead of a moving vehicle to be worth having. Sophie Lund Rasmussen of Oxford's Wildlife Conservation Research Unit, who led the work, said the next step is “to find collaborators within the car industry to fund and design sound repellents for cars.” Her colleague Professor David Macdonald put the pleasure of it well: “It is especially exciting when research motivated by conservation leads to a fundamental new discovery about a species biology which, full circle, in turn offers a new avenue for conservation.”