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116 Nature

Reptiles

Rattle

VENOM

Eyes move

independently

of each

other

Mitten-like feet,

formed from joined,

opposing toes, give the

chameleon a firm grip

HOW DO REPTILES ESCAPE FROM DANGER?

Many reptiles hide, or are camouflaged to blend

in with their surroundings. Some are speedy and

agile, and can scurry off at lightning speed.

Others are brightly coloured to warn

predators that they are venomous.

Some lizards can break off their tail in

order to escape, growing a new one

through. REGENERATION.

This group of scaly-skinned, backboned animals includes

snakes, lizards, crocodiles, hard-shelled turtles, and the

tuatara, from New Zealand. Most reptiles live on land but

turtles, crocodiles, and some snakes live in water. Nearly

all reptilies are equipped with senses similar to humans.

4 RATTLESNAKE

Venomous rattlesnakes send out a

warning to large animals by shaking the

rattle of loose scales on their tail.

HOW DOES SNAKE VENOM WORK?

Snake venom works on victims in two main ways.

The venom of snakes such as vipers causes death

by damaging the prey’s body tissues and blood.

Other snakes produce neurotoxins, which attack

the victim’s nervous system, paralysing the heart,

breathing system, and muscles.

The majority of snakes kill their prey with

venom produced by glands in their heads.

The glands pump poison through long,

pointed teeth called fangs, which bite

deep into their prey.

4 RED-TAILED RACER

Snakes gather molecules with their tongues,

then transfer them to a gland on the roof of

the mouth called the Jacobson‘s organ. This

gland is very sensitive and can detect distant

prey. Some vipers can detect the body heat of

prey using special pits near to their eyes.

WHAT DO REPTILES EAT?

Most reptiles are active predators. Lizards hunt mainly

insects. Snakes target prey such as rodents and birds.

Some snakes subdue their victims with. VENOM.

Crocodiles prey on creatures as large as wildebeest.

Turtles and terrapins eat mainly fish and invertebrates.

Tortoises, which live on land, feed mostly on plants.

Forked tongue picks up scent

particles from the air

REPTILE CLASSIFICATION

• There are around 8,000
  species of reptile split into
  four different orders.


• Snakes and lizards belong to
  the same order – Squamata.
  Altogether there are more
  than 7,000 species of snakes
  and lizards.
  
  
  • The second-largest order,
    Chelonia, includes all turtles,
    tortoises, and terrapins.
  
  
  • Crocodiles and their relatives
    make up the order Crocodilia.
  
  
  • The tuatara is the last living
    member of its order. The rest
    died out 100 million years ago.
  
  
  
  

FANGS OUT 3

Vipers lift their

fangs forward just

before biting, as this

model shows. At rest,

the fangs are held

against the roof of

the mouth.

Venom

gland

Hollow

fangs

HOW MANY SNAKES ARE DEADLY TO HUMANS?

Fewer than 10 per cent of snakes produce venom

strong enough to kill a person. Vipers produce large

quantities of venom – people bitten by diamondback

rattlesnakes have been known to die in under an

hour. The Australian inland taipan is thought to be

the world’s most deadly snake. Sea snakes are also

highly poisonous, but they rarely bite humans.