Climatic change in Neocene has strongly affected upon life of various Earth inhabitants. Some of them had to abandon their habitats, other oness had died out, and third ones had received great opportunities for evolution and had turned to prospering species. Humidifying of climate has caused reduction of desert areas and expansion of tropical rainforests zone. Some of inhabitants of open spaces have to found convenient places for life in forests, and than evolved to true wood inhabitants. In Australia which even after intervention of humans has kept an originality of fauna and flora, amazing abilities to adaptation were shown by echidna - the inhabitant of savannas and light forests. It had turned to true wood inhabitant, and besides it had changed to the excellent tree-climber. To see such animal on the tree is not so such unusual thing as it seems at first sight. Among tree-climbers in different continents there were kangaroo, porcupines and even ground tortoises, not to mention toads and frogs. Therefore the wood echidna of Neocene epoch, sauntering along tree branches, does not seem as something unusual on their background. This is rather large animal: its body length is up to 70 cm, heads with long proboscis is about 30 cm long. Slowly moving in tree crones wood echidna outwardly resembles a hybrid of bear and anteater. The wood echidna had kept characteristic shape of these animals, but had got additional features of adaptation to clambering habit of life. Its paws which are quickly digging off the firm dry ground, now equally easily break rotten wood or strong cover of termitary. Claws becoming more bent cling to bark and branches, permitting the animal to make walks at 30-meter height so easily, as if on firm ground. For more tenacious grip thumbs on forepaws began to oppose partly to fingers. On hinder legs feet are turned back, but it at all does not prevent this animal to move. Even on the contrary to it, using such feet it is easier to climb down headfirst along the tree trunk. The little toe on hinder legs became a certain analogue of the thumb: it can be opposed to other toes too and serves for branch gripping. This animal is very strong: by paws the echidna breaks trunks of trees beginning to rot and turns out from trunk thick boughs, searching for ants and termites. Body of the wood echidna is massive and heavy-build. The tail of animal is very short; it serves practically only for fat accumulation. The muzzle of this echidna is long, tiny mouth opens on its tip. Main food of animal includes insects, usually ants and termites, and the main instrument of their catching is the long tongue covered with sticky saliva. Except for ants and termites, the echidna eats larvae of beetles searching them in pierced trunks of dead trees, and also insects living among epiphytic plants. The wood echidna is able even to plunder trap leaves of insectivorous plants, catching from them insects floating in digestive liquid secreted by leaves. Sometimes it simply drinks this digestive juice with insects. One more dainty for the echidna includes bird eggs. Having found a nest, the echidna drives hatching bird out from it, accurately pierces an egg-shell by claw tip and licks by tongue the egg completely. The animal exhausts all eggs in nest though sometimes it is attacked not only by nest owners, but also by their numerous neighbours have flied to help. But what can birds make with the prickly robber surpassing them many times in weight? Eyes of the wood echidna are very small, and auricles are not present at all. This animal is short-sighted, and the prickly armor perfectly protects it from any predator of Australian and New Guinean woods, therefore the wood echidna can not react (at least, externally) to loud alarm cries of wood inhabitants. But sense of smell and touch at it are very sharp: the animal easily will feel, as on branch any bug or spider creeps, not seeing it at all. Colouring of animal began more contrast, than at its ancestor: needles are ivory-colored, top of body is light, and stomach is dark, covered with short thin fur. At the wood echidna there is very dense and thick skin, therefore stings of ants and termites are not harmful to it. Even army ants killing all alive on their way, do not harm this phlegmatic animal: unless they will inflict some stings to sensitive proboscis or between toes. The animal has natural immunity to their poison, therefore the echidna does not avoid their attacks: such attack does not harm to it, and in it there is even such benefit – ants at the same time kill blood-sucking insects in wool of the huge echidna. If insects (and also larger enemies) appear too importunate, the wood echidna sprinkles out a jet of musk liquid from special glands. Its sickening smell easily will drive off the most persevering predator. The wood echidna is real wood tramp. It has no precisely bordered territory, and does not protect residence from neighbours. Some animals can peacefully food on the same tree, and even to ravage one termitary in common, not paying attention against each other. During such meetings pairing happens more often. Courtship ritual at the wood echidna is not present, and the breeding season lasts all the year round. Not changing traditions of ancestors, wood echidna lays eggs. In its clutch there are 1 - 2 rather large eggs (with small chicken egg-sized ones), covered with white skinny shell. During formation of eggs because of hormonal influence the cross skin plica on the stomach of the female is increasing and turning to brood pouch. The female lays eggs, lying on back so that the tail appeared above a head. Then the egg rolls down to the pouch itself from oviduct. The incubating lasts about three weeks. Cubs hatch underdeveloped, looking more similar to embryons. They lick milk, squeezing from pouch walls. Usually from two cubs only one cub survives. It grows quickly, and at the age of two months (when it leaves mother’s pouch), the cub weighs already about half-kilogrann. It is covered with grey naked skin, but at it the short proboscis characteristic for these animals is visible. Claws of it still soft and short but after the cub has left the pouch, it literally starts to increase from different directions: practically simultaneously at it needles, wool and claws grow. While the cub is still small, its unique protection is musk liquid with which it excretes plentifully at a fright. The female regularly visits it (approximately twice per day) and feeds with milk. For this purpose it lies down on back in forked crown of branches, and the cub licks off the milk flowing down from pouch to stomach. But gradually the cub also starts to catch insects. At the age of three months the cub already starts to wander in wood canopy with mother, studiing to swarm up lianas and to search for insect nests. At the age of eight months it reaches length about 70 cm and already is completely independent. At the age of 20 months the young female already can lay the first egg and this surprising animal can live up to the age of 60 - 70 years.