New study suggests ultrasound could help save hedgehogs - University of Oxford

Researchers at the University of Oxford have suggested that ultrasound-repellers could help reduce hedgehog deaths by cars. The proposal is based on new findings, published today (11 March 2026) in Biology Letters, which demonstrate for the first time that hedgehogs can hear high-frequency ultrasound.

The European hedgehog (Erinaceus europaeus) is one of our best-loved mammals, but populations are in grave decline with the species being newly classed as “near threatened” by the International Union for Conservation of Nature in 2024. A major cause of hedgehog deaths is road traffic accidents, which are thought to kill up to one in three hedgehogs in local populations.

A new study now suggests that ultrasound repellers could be used to deter hedgehogs from roads, reducing the number killed by cars. Up to now, it was unknown whether hedgehogs could hear this range.

Lead researcher Assistant Professor Sophie Lund Rasmussen (Wildlife Conservation Research Unit/Department of Biology, University of Oxford and University of Copenhagen) said: ‘Having discovered that hedgehogs can hear in ultrasound, the next stage will be to find collaborators within the car industry to fund and design sound repellents for cars. If our future research shows that it proves possible to design an effective device to keep hedgehogs away from cars, this could have a significant impact in reducing the threat of road traffic to the declining European hedgehog.’