Sharks and rays also share the same kind of skin: instead of scales, they have small tooth-like spikes called dentils. The spikes are so sharp that shark skin has long been used as sandpaper.

A giraffe can clean its ears with its 50cm (20 in) tongue.

A snail has two pairs of tentacles on its head. One pair is longer than the other and houses the eyes. The shorter pair is used for smelling and feeling its way around.

A group of geese on the ground is a gaggle – a group of geese in the air is a skein.

The sailfish is the fastest swimmer, reaching 109 km/h (68 mph).