Close up of mahjong tiles arranged perfectly for play against a black backdrop.

London, England: Elephant playing with a large ball, pushing it with head, kicking and lifting the ball with its trunk.

The Gambia: High view looking down onto local children playing with ball on beach at sunset, image dissolves into closer view

An American black bear cub sits on the forest floor, chewing a long branch. It then falls backwards onto its mother. When the mother bear tries to nurture her cub, the cub starts to play fight.

Various shots of a lion cub playing in the arms of an adult lioness. Lion cub attempts to jump on adult lion's back. Lake Manyara National Park, Tanzania, Africa.

A restless American black bear cub sits on the forest floor, playing with a long branch.

Berlin, Germany: Group of young men playing basketball in front of Neptune Fountain (Neptunbrunnen) in evening light.

A group of guianan black spider-monkeys feeding and playing.

Beluga whales playing with a red ball in an aquarium. The whales bounce the ball from their mouths and pass it on to one another.

Medium close up of hands shuffling mahjong tiles and arranging pieces for play.

An American black bear cub plays against a tree then wanders off to join another cub and the mother bear.

A Woolly monkey plays with the baby of another monkey. The baby is clinging onto its mother. The mother then wanders off with its baby.

Hands of unidentifiable people playing Chinese Chess.

England: Group of anonymous children playing cricket on a village green. They are all dressed in white cricket outfits and are bouncing a ball on their bats.

An elephant calf plays near her mother.

Teenage boys playing football about in an urban recreation area in Paris, France.

Two adult Woolly monkeys sit on a thick branch. One of the Woolly monkeys plays with the baby of the other monkey. The baby is clinging onto its mother.

Various shots of a lion family. A lion cub jumps onto an adult lion and tumbles off landing on its back. Two lion cubs begin to play fight with one another. Lion cub licks and paws the nose of a sleeping adult lion. Lake Manyara National Park Tanzania, Africa.

Underwater shot of a California sea lion swimming near the sea bed. It finds a sea cucumber and plays with it.

An American black bear climbs quickly up a tree and rests on a branch.

Two pairs of feet belonging to young children slide down metal slide in outdoor playground area, one after the other feet wearing trainers slide towards camera then stop

Silhouette of school girl jumping over skipping rope watched by other children in playground, seen from ground level on bright sunny winter day

Silhouette of a California sea lion posing underwater. The sun can be seen through the water's surface.

Blurred image of Secondary schoolchildren running around in playground wearing uniform and winter clothing

Close-up shot of a family of Eastern chimpanzees relaxing in a forest clearing in the Gombe National Park, Tanzania. The baby chimpanzees are very restless and are pestering their parents. One of the baby chimpanzees is climbing all over its parents and ends up lying on the mother.

Close-up shot of the faces of two camels.

A restless American black bear sits on some branches high up in a tree, while another bear tries to climb further up the tree.

Australia: Aerial shot of a humpback whale lobtailing (or tail slapping), whereby it slaps its tail flukes onto the surface of the water.

A pair of child's feet slide down metal slide in outside playground area towards camera

Young girl with long blonde hair wearing pink top slides down plastic orange spiral slide in outdoor playground

A cricket match in progress.

Australia: Aerial shot of a humpback whale lobtailing (or tail slapping), whereby it slaps its tail flukes onto the surface of the water. A big splash is created as the tail hits the water.

A restless American black bear cub sits on the forest floor, chewing a long branch, then sticking out its long tongue.

A group of teenage schoolboys in winter clothing having a snowball fight in St James's Park in London, England. Snow covers the ground and the bare branches of trees in the background.

Close-up shot of a restless baby Eastern chimpanzee lying on the ground.

Close-up shot of a family of Eastern chimpanzees relaxing in a forest clearing in the Gombe National Park, Tanzania. The baby chimpanzees are very restless and are pestering their parents.

Feet and legs of child wearing jeans and white trainers seen dangling from green leafy tree, child's head and body are obscured by leaves

Close-up shot of a family of Eastern chimpanzees relaxing in a forest clearing in the Gombe National Park, Tanzania. The baby chimpanzees are very restless and are pestering their parents. One of the baby chimpanzees is climbing all over its parents and clinging onto them.

Blurred school children seen through bars of school gate running around in inner city school playground. Railings of gate framing the shot.

High angle shot overlooking hands shuffling mahjong tiles.

Underwater shot of a California sea lion swimming near the sea bed.

England: Legs of a cricket player by two wickets on a village green. The player bats a ball towards players out on the green.