Snipfact:

  Ticks can carry diseases such as encephalitis and Lyme disease. Mites and chiggers (baby mites) cause skin diseases and may transmit typhus.

  Some of the tiny creature that feed on us may also transmit diseases. Tsetse flies carry African sleeping sickness. Mosquitoes can infect humans with diseases such as malaria, dengue fever and yellow fever when they bite. Malaria has killed more people in human history than any other disease.

  Follicle mites are in everyone’s hair, even among our eyelashes. They were first described by 19th-century scientist Richard Owen (the man who first named dinosaurs), but are so tiny that few people have ever seen them or even aware that they are there.

  Parasites such as roundworms, hookworms, flukes and tapeworms – which can grow as long as 9.75 m (32 ft) – can live inside our bodies. They may cause such diseases as elephantiasis, in which the patient’s limbs swell to gigantic sizes. Head lice live on human heads and feed on blood. The lice lay little white eggs, called nits, which cling to individual hairs.

  As many as 1000 trillion viruses and bacteria live on each of us. However much we wash, there are always ten million or so bacteria on every square centimetre of our skin. There are also many tiny creatures called parasites, which can live inside or on the human body, feeding on our blood.

  The smelliest frog is the Venezuela skunk frog, Which was discovered in 1991. It warns off its enemies by releasing a bad-smelling chemical identical to the one produced by skunks.

  The poison-arrow frogs of Central and South America are the mostly deadly. The world’s most poisonous amphibian is the golden poison-arrow frog of western Colombia. One adult contains enough highly toxic poison in its skin to kill 1,000 people.

  The green toad has been seen at 8,000 m (26,247) in the Himalayas and toads have been discovered more than 3,048 m down a coal mine

  The marine toad lays 35,000 eggs a year, but the Cuban arrow-poison frog lays only one egg.

  In 2006, 20 previously unknown frog species were discovered in an expedition to Indonesia including a tiny microhylid frog that measures less than 14 mm

  The smallest frog and the world’s smallest amphibian is the Eleutherodactylus limbatus frog, which measures only 8.5–12 mm.

  The world’s largest toad is the South American marine toad. It can have a body length of over 23 cm and weigh up to 1.2 kg

  The largest tree frog is Hyla vasta, which lives only on the island of Hispaniola. It is more than 12 cm long and has huge round finger an toe disks which grip like superglue.

  The world’s largest known frog is the goliath frog, which lives in central Africa. It measures up to 87.63 cm long and weighs as much as 3.66 kg.

  An amphibian is a vertebrate animal that spends at least some of its life in water. Its skin is not scaly. There are about 5,578 species of amphibian, divided into: Frogs and toads 4,896 species Newts and salamanders 517 species Caecilians (legless amphibians) 165 species

  The thread snake is rarely longer than 108 mm. The spotted dwarf adder is the smallest venomous snake at 22.r cm long.

  Many people believe that the South American anaconda is the largest snake. There are reports of anacondas up to 36.5 m long, but this has never been proved. The reticulated or royal python is probably the longest snake up to 10.7 m, but the anaconda may be the heaviest at up to 230 kg.

  Crocodile (India, Sri Lanka) 4–5 m (13.1–16.4 ft) Saltwater crocodile (Southeast Asia, Australia) 6–7 m (19.7–23 ft) Cuban crocodile (Cuba) 3.5 m (11.5 ft) Saimese crocodile (Southeast Asia, very rare) 3–4 m (9.8–13.1 ft) African dwarf crocodile (Central and West Africa) 1.9 m (6.2 ft) False gharial or gavial (Southeast Asia) 5 m (16.4 ft) Indian gavial or gharial (India, Pakistan, Bangladesh, Nepal) 5–6 m (16.4–19.7 ft)

  American alligator (southern USA) 4–4.5 m (13.1–14.8 ft) Chinese alligator (China) 2 m (6.6 ft) Spectacled caiman (South America) 2–2.5 m (6.6–8.2 ft) Broad-snouted caiman (South America) 2 m (6.6 ft) Yacare caiman (South America) 2.5–3 m (8.2–9.8ft) Black caiman (South America) 4–6 m (1(13.1 19.7 ft) Cuvier’s dwarf caiman (South America) 1.5–1.6 m (4.9 – 5.2 ft) Schneider’s or Smooth-footed caiman (South America) 1.7–2.3 m (5.6–7.5 ft)