21.The territory of the adult platypus covers an area of about 7 km².
Platypuses live in oval-shaped burrows located near the water surface.
22.They have many natural enemies: eagles, owls, hawks, snakes, warblers, crocodiles and hydromys.
Platypuses are not an endangered species, their mortality rate is not high, but nevertheless they are under protection.
23.Platypuses are equipped with electroreceptors, which makes them a phenomenon among modern mammals.
Thanks to them, they track their prey through changes in the electric field. The platypus can perceive electrical stimuli from the environment, just like sharks. Electroreceptors are located in its skin's special grooves. The beak determines the source of the electric field by comparing differences in signal strength between different receptors. This is evidenced by the fact that during the hunt it moves its head from side to side and "calculates" the distance to the prey. It uses neither smell nor sight during the hunt.
24.They developed special spurs on the ankles of their hind legs from which venom is secreted.
Only males possess the toxin. Females pose no threat because their spurs disappear before the first year of life. The venom is not lethal to humans, but the sting causes severe pain, making normal functioning impossible. After a sting, swelling appears around the wound, spreading to the entire limb. Venom production increases during the reproductive period of platypus and it is believed that males use the toxin to assert their dominance rather than to kill the intruder.
25.Another feature typical of reptiles found in platypuses is the presence of a cloaca.
It is connected to both the intestine and the reproductive system. They have no scrotum, the testicles do not descend and are located in the abdomen.
26.The platypus has a large brain.
27.Observations of platypuses have shown that they can be both sedentary and migratory animals.
28.Platypuses lay eggs, which is also a trait inherited after reptilian ancestors.
The breeding season lasts from June to October. During breeding, females build a new burrow up to 20 m deep, with features blocking access to the rest of the den. The inside of the burrow is covered with wet leaves and reeds (the female bears the leaves by holding them under her tail). The female has two ovaries, but only one is active. In one litter she lays from 1-3 small eggs with leathery shells. Their diameter is about 11 mm. The female hatches the eggs for about 10 days and warms them by wrapping herself around them. After 10 days, blind and bald young hatch and are fed with milk produced not by the nipples, but through pores in the skin from which the milk comes out. The milk feeding continues for 3-4 months and after this time the juveniles leave the burrow.
29.Platypuses live up to 11 years in the wild and up to 17 in captivity.
30.In reserves, the platypus can be seen in special aquariums, as of 2013 only in Australia.