Ultrasound repellers could keep hedgehogs off roads, scientists hope

Electrodes detected that the hedgehog’s brainstem fired when signals were played across a range of 4 to 85kHz, demonstrating they can hear very high frequencies in the ultrasound range. Photograph: Alamy/PA

Hedgehogs have been discovered to hear high-frequency ultrasound, raising hopes that they could be deterred from dangerous roads with ultrasound repellers.

Vehicles are estimated to kill up to one in three hedgehogs, a big factor in the much-loved mammal’s drastic decline across Europe over recent decades.