Struggle to sleep in a strange bed? Scientists have uncovered why

Just as birds and dolphins stay alert for predators whilst asleep, it seems that half of the human brain may remain similarly watchful in new surroundings

The pillows are firm, the duvet is snug, and the sheets are pristine. But even in the comfort of a luxury hotel, your first night's sleep can be dreadful compared to a night in your own bed.

The phenomenon is so familiar to sleep researchers that it has its own name: the first night effect. For some reason, when we tuck ourselves up under a new roof, we often have a troubled night and wake up feeling groggy and tired.