A surprising discovery about hedgehog hearing could lead to ultrasonic “warning signals” that help keep them away from deadly roads. Credit: Shutterstock Scientists at the University of Oxford say ultrasonic sound devices might one day help reduce the number of hedgehogs killed by cars. Their idea stems from new research published March 11 in Biology Letters showing for the first time that hedgehogs are capable of hearing high-frequency ultrasound. The European hedgehog is one of Europe's most