'The best bat experience in Britain': Cambridge's nocturnal punting safaris

A trip following bats along the river Cam has become one of the hottest tickets in town - and raised money for their protection

It's an impossibly idyllic early summer evening on the Backs of Cambridge. A blackbird flutes as a man pressure-washes a table outside a hotel. Mating flies drift on the breeze, alongside a whiff of marijuana. A student lies flat on the riverbank, feet in the water.

Punting on the river Cam has stopped for the night but one boat slips into the gathering dusk: the Bat Punt Safari.