FEEDING

Unlike plants, animals cannot make food from sunlight.
Animals have to feed to produce the energy they need to grow, move, and
reproduce. Some animals eat only plants, others eat meat, and some eat both.
Most animals have a gut with a mouth at one end and an anus at the other. Food
is broken down as it passes from one end of the gut to the other. The nutrients
are absorbed into the body in a process called DIGESTION.

Many aquatic animals, including whales and basking sharks, take in
food by filter feeding. Fan worms that live on seabeds use the tentacles around
their mouths to filter food. As they draw water towards them with their
tentacles, food particles are trapped in their tentacles with mucus. The food
is then passed into their mouths.

PREDATOR AND PREY

Ospreys are birds of prey that feed entirely on fish. Like all
predators, they have specially adapted features to help them catch prey. Osprey
have powerful wings and feet that enable them to swoop down and grab fish.
Birds do not have teeth but a muscular organ in their digestive system called a
gizzard for grinding up food. This organ also prevents harmful bones from
passing into the birds’ intestines.

ANGLER FISH

Some deep-sea predators, such as angler fish, use lures to catch
their prey. In deep water, food is often scarce, so attracting prey rather than
chasing it saves energy. The angler fish’s lure glows in the dark. Once
the prey is lured near enough, the enormous jaws of the fish snap shut.

OMNIVORES

Animals that eat both plants and animals are called omnivores. They
are highly adaptable and use whatever food they can get hold of. Racoons, with
their skilful hands, are particularly successful at finding food. Their diet
ranges from fish and young birds to shoots and berries. Some omnivores are at
home in urban areas, surviving on garden produce and waste.

HONEYPOT ANT

Animals have found remarkable ways to hoard food. Honeypot ants
create larders by selecting newly hatched worker ants to act as storage
vessels. They are fed a mixture of honey and nectar, causing their abdomens to
swell. In the dry season, when there is less food about, the other ants entice
them to regurgitate droplets of food so they can all drink.

DIGESTION

During digestion, animals break down food into pieces
small enough to be absorbed. The process is made quicker by chemicals in the
gut called enzymes. In some invertebrate animals, digestion begins outside the
body, in others food is taken in through the mouth and then digested. In
mammals, food is sometimes chewed before swallowing.

The teeth of a tiger are highly specialized for gripping and
eating meat. The long, pointed canine teeth are used for biting into an
animal’s neck. The carnassial (cheek) teeth pull flesh off bones or
slice up meat with a scissor-like action.

SPIDER CATCHING FLY

Many spiders trap their prey in webs, paralysing any animal that
becomes stuck with a venomous bite. Spiders pour digestive enzymes into the
prey and then suck in the resulting liquid. They can live for weeks without
eating because they are able to store nutrients.

HERBIVORE RHINO

Plant-eating animals are known as herbivores. Plants may be easy
to find but are sometimes low in nutrients. To survive, herbivores, like this
rhinoceros, have to spend much of the day eating. They also have special
digestive systems that get the maximum nutrition from food.