Scratching that itch: tests on mice show urge is hard-wired into brain

Research seeking to unpick the reasons for contagious itching suggest it is not linked to empathy but is programmed into the brain's neurocircuitry

Humans and monkeys are not alone in finding they can catch an itch. Researchers have discovered that mice also start scratching when they see others at it - and worked out why.

Contagious itching has long intrigued scientists, with various suggestions cropping up to explain the phenomenon, among them the possibility that it might help social animals curb the spread of parasites. Previous research has also suggested that it is more prevalent among highly neurotic people.