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).

In Denmark there are twice as many pigs as people.

Measured in straight flight, the spine-tailed swift is the fastest bird. It flies 170 km/h (106 mph). Second fastest is the Frigate, which reaches 150 km/h (94 mph).

Of the 650 types of leeches, only the Hirudo medicinalis is used for medical treatments.

The coyote is a member of the dog family and its scientific name, “canis latrans” means barking dog.

The tongue of a blue whale is as long as an elephant.

The Big Five is a group of animals of Africa: cape buffalo, elephant, leopard, lion and rhino. The term “Big Five” was coined by hunters who referred to the difficulty in hunting these wild animals because of their ferocity when cornered.

Animals also are either right-handed or left-handed. Polar bears are left-handed – and so is Kermit the Frog.

Sheep are mentioned 45 times and goats 88 times in the Bible. Dogs are mentioned 14 times and lions 89 times, but domestic cats are not mentioned.

The South American giant anteater eats more than 30,000 ants a day.

The largest jellyfish ever caught measured 2,3 m (7’6″) across the bell with a tentacle of 36 m (120 ft) long.

A dog was the first in space and a sheep, a duck and a rooster the first to fly in a hot air balloon.

The scales of a crocodile are made of certain, the same substance that hooves and fingernails are made of.

Some bird species, usually flightless birds, have only a lower eyelid, whereas pigeons use upper and lower lids to blink.

75% of wild birds die before they are 6 months old.

The heaviest crustacean ever found was a lobster weighing 19 kg (42 lb), caught in 1934.

An annoyed camel will spit at a person.

The giant squid has the biggest eyes of any animal: its eyes measure 40 cm (16 in) in diameter.

Fish and insects do not have eyelids – their eyes are protected by a hardened lens.

Domestic cats purr at about 26 cycles per second, the same frequency as an idling diesel engine.

Mammals are the only animals with flaps around the ears.