A baby monkey nodded off for 10 hours after he overdosed on coffee.

The naughty baby macaque swiped a tourist's caffeine out of his hand while he was speeding along on a bike in Bangkok's Bang Khun Thien district.

Just seconds after gulping the caffeinated beverage, the little monkey collapsed.

Vets quickly arrived on the scene and administered a carbon and saline solution before he was escorted to the animal hospital where he was watched until he came round.

The monkey – who is apparently six months old - woke up at 3am the next day. He was released once the vets were convinced about his recovery.