Animals Behaviour

Picture of hedgehogs A hedgehog is any of the small spiny mammals of the subfamily Erinaceinae and the order Erinaceomorpha.

In order to survive, all animals must eat and avoid being eaten. They also driven to reproduce so their species does not die out. Most animal behaviour is geared to these basic goals. Some behaviour is learned, the rest is controlled by instinct.


Picture of a Pufferfish: Pufferfish defend themselves by inflating their bodies with water. Along with their spines, this makes them harder for bigger fish to swallow. Many other species are also covered with spines to protect them from even the largest of predators.

How do animals defend themselves?
Animals behave in many different ways to escape danger. Some are camouflaged to blend in with their surroundings. Behaviour such as keeping still completes their disguise. Some species defend themselves with more complex behaviour, such as pretending to be injured or dead. Hedgehogs and armadillos roll into a ball to ward off predators.


Picture of Armadillo

Some interesting facts about armadillos include:

• Armadillos enjoy eating ants and they can devour up to 40,000 in one meal. Each armadillo eats up to 200 lbs of bugs a year. That's over 6 billion pounds of bugs for the entire US population of 'dillos per year.

• Armadillos sleep over 17 hours a day, with 3 hours of REM sleep. Humans only have 2 hours of REM sleep.

• Armadillos are the only mammals that always give birth to four identical young. All four develop from the same egg and share the same placenta.

How important is instinct?
Instinct plays a major part in the behaviour of animals, especially animals that are not reared by their parents. For example, when danger threatens, snals instinctively withdraw inside their shells. Animals also learn by trial and error, repeating actions that are productive and abandoning ones that are not.


Baby birds such as goslings (young geese) instinctively follow the first animal they see after hatching. This is usually their own mother, but goslings have also been known to waddle around after humans and dogs.

Why do animals follow regular cycles?
All animals follow regular cycles to help them survive. Many creatures are active by day, when their sense work best. Others come out at night to avoid predators, or take advantage of feeding opportunities. Most animals also follow yearly cycles, usually bearing young when food is abundant.



Clownfish hide from their enemies among the stinging tentacles of sea anemones. The fish's skin releases chemicals that stop the anemone's cells from firing. Clownfish are found in tropical seas around the world.

Feeding In Animals

Picture of Grizzly bear: Bears eat many food, including fruit, nuts, roots, honey, carrion (dead animals), small mammals, and salmon too.

All animals must eat other organisms to survive. Animals can be divided into two main groups, according to their feeding habits -- carnivores (meat-eaters) and herbivores (plant-eaters). Most animals eat either meat or plants, but omnivores eat both. The word omnivore means 'everything-eater'. Bears, humans and pigs are omnivores. In our diet, we carry on the traditions of our early ancestors, who killed game and also gathered berries and nuts.

Most carnivores are predators -- animals that hunt other animals for food. Predators usually have sharp teeth, claws or beaks to tear apart their prey. Animal flesh is nourishing, so predators do not have to kill very often. It is also easy to digest.



A shark's teeth are sharp and pointed to rip prey to pieces. They grow in rows and are continually shed and replaced. Some species may get through as many as 30000 teeth in a lifetime. Not all sharks are predators -- the largest, the whale shark, is a filter-feeder.

Filter-feeding is a feeding method works by sifting large amounts of small organisms from water. It is a bit like using a sieve to catch prey. Filter-feeders come in a variety of shapes and sizes -- barnacles, flamingos, and baleen whales (including the blue whale) all feed in this way.

Top predators such as lions, sharks and eagles rely on strength and speed to overcome their victims. Smaller or weaker hunters may rely on stealth or special techniques to capture prey. Some predators, such as wolves, hunt in packs. Spiders spin webs to tangle up victims. Rattlesnakes kill their prey with venom.




Hyenas and vultures are scavengers -- meat-eaters that get their food from the abandoned kills of others.

Scavengers are animals that feed on dead or injured animals. Scavengers are not usually held in high esteem, but they have a job to do: they clean the earth of organic garbage.


Some birds, such as toucan, specialize in eating fruit. Toucan's bill is extra-large for probing through vegetation. Packed with sugars, fruit is much more nourishing than leaves and far easier to digest. However, it is also more scattered and harder to find. Many fruit-eating birds sometimes have to eat insects. It is only in tropical rainforest that birds can find fruit all year round.

The jaws, teeth, and stomachs of herbivores are designed to tackle tough plant food. Compared with meat, plants are not very nourishing, so many herbivores spend long hours feeding.

Plants contain tough cellulose, which is hard to digest. Many herbivores' stomachs are filled with microbes, which break down cellulose. Some plant-eaters, such as cattle, have stomachs with several chambers. After passing through some chambers, food is returned to the mouth for more chewing to help break it down.

Herbivores do not need quick wits to capture their food, but they must be swift or have some means of defence to avoid being eaten by predators. Many are camouflaged to blend in with their surroundings, so that hunters do not notice them. Others have tough skin, spines or even poison to put off enemies.

Animals Communication

Picture of Vervet Monkeys

Animals communicate with their own kind or other species to coordinate the search for food, attract mates, bring up young, or escape from danger. Various species send signals using sight, sounds, body language, touch, scent, complex chemicals, or a combination of all of these.




Intelligent mammals such as chimpanzees communicate with others using sounds, scent, touch, body language, and facial expressions. Chimps can even be taught to communicate with humans using sign language.

When do animals use visual signals?
Close-range visual signals are used to send a variety of messages, such as "Food is near" or "Keep away!" Birds from peacocks to robins attract mates using bright colours. Fireflies do the same with light. The white flash of a fleeing rabbit's tail warns others of danger.

Why do animals communicate with sound?
Sound signals carry over considerable distances and give information immediately. Songbirds and howler monkeys call to establish territories. Whales, frogs, and crickets sing to attract a mate. Vervet monkeys warn others of different enemies by using different sounds.



A wolf can give over 20 different messages by raising or flattening its ears, back, tail and neck hairs, or by baring or hiding its teeth.

Do animals always tell the truth?
When animals communicate with their enemies, their messages are not always truthful. Dogs, cats and other animals raise their hackles, arch their backs, or puff themselves up to look bigger. Opossums play dead to fool their enemies. Some animals mimic the appearance of dangerous creatures.



Pheromones released by a queen bee prevent other fertile females from developing. If the queen goes missing and the pheromones are no longer released, new queens are reared. One of these will eventually take over the hive.

Why do animals use pheromones?
Animals use scent signals called pheromones to affect the behaviour of others. These complex chemicals, which include hormones, are most often transferred by air. Female moths release pheromones to attract males. In ant, bee, and termite colonies, the queen releases pheromones to convey all sorts of messages to the rest of the colony.



Visual signals can be used for defence. This hawkmoth caterpillar (picture on the left) has evolved a tail that looks like a snake's head. Predators are scared off by the disguise, even though the caterpillar is harmless.

Animals Facts

The cheetah is the world's fastest land animal, capable of speed of up to 96km/h in short bursts. It hunts by ambush, creeping as close as it can to its prey before rushing in for the kill.

Animals are grouped into two main types -- vertebrates with an inner skeleton, including a backbone and invertebrates without a backbone. As many as ten million species (different kinds) of animals -- all with their own modes of behaviour live on earth.


A chameleon is camouflaged to blend in with its surroundings, and moves around slowly to avoid detection by its predators and prey. To feed, the chameleon shoots out its tongue at a lightning-fast speed to hit insects before they have time to react.

Which features do all animals have in common?
All animals have bodies made up of many different cells and eat other organisms to survive. Unlike plants or fungi, which are rooted in one place, animals move about to find food, escape from enemies, and find a mate. Almost all animals breathe oxygen, either from the air or from water.

What is the world's fastest animals?
The world's fastest animal is the peregrine falcon, which can exceed 200km/h when diving through the air after prey. The fastest-powered flight is that of the spine-tailed swift. It travels at up to 170km/h. The quickest animal in water is the sailfish, which can swim at up to 109km/h.

What are warm-blooded animals?
Warm-blooded animals are those that generate their own body heat from food. Birds and mammals are warm-blooded. All other animals, including fish, reptiles, amphibians, and insects, are cold-blooded. Their body temperatures rise and fall with the temperature of their surroundings. These animals are less active in cold weather but require less food.


The Asian Elephant is the world's second largest land animal (the African elephant is the largest). Like all mammals, it is warm-blooded. Due to the size, elephants can have trouble keeping cool. One solution is to seek water. Elephants also flap their ears to cool the blood flowing through them.

How big do animals grow?
Some animals grow to enormous sizes. The world's biggest animal, the blue whale, may reach 28m long and weigh almost 150 tonnes. On the other hand, some animals are too small to be seen with the naked eye. The world's tiniest animals are creatures called mesozoans. They consist of fewer than 50 cells and measure less than 0.5mm in length.



Leaf-cutter ants ( Atta sexdens ) live in colonies of closely related individuals, all hatched from eggs laid by a single queen. Most become worker ants.