Is ? A tortoise is not a mammal. Taxonomically, it belongs to Reptilia, Chelonia, Cheloniidae, so it belongs to reptiles. This kind of animal often has a hard carapace on its body, and when it is in danger, it can retract its head, tail and limbs into the shell to avoid being attacked by enemy creatures. However, some species are limited by their shape, such as the head of snapping turtles and the limbs of turtles, which can not be retracted.
of mammals? 1. Body hair: The body surface of mammals is generally hairy. The role of body hair is to protect the body, but also to isolate the air, thus playing the role of heat preservation. It should be noted that not all mammals have hair, but naked moles on land and dolphins and whales in the sea do not.
2. Constant body temperature: Almost all mammals are thermostatic animals. The biggest advantage of constant temperature over variable temperature is that it can adapt to environmental changes. Usually, poikilothermic animals will become inactive in a lower temperature environment, and some will enter hibernation. Of course, it does not mean that warm-blooded animals will not hibernate, for example, bears will hibernate in winter.
3. Viviparous lactation: The most remarkable feature of mammals is viviparous lactation. The embryo will develop in the mother's body, then be produced by the mother's body, and provide milk for feeding. Because of this characteristic, they have larger brain capacity, highly developed vision and smell compared with other animals.
