There is no such thing as insulation in the animal world

Heat preservation? Kangaroo hemp sack.

Under the penguin's skirt, haha.

Thermotherms (warm-blooded) often require insulation, and terrestrial animals do so by sequestering a layer of air in their feathers or hair. Birds are covered with feathers. The heat insulation effect of fluff is very good, so there are fluff clothing, mattresses and sleeping bag products in human society.

Feathers are also found in some dinosaurs. Therefore, it is speculated that dinosaurs were also homeothermic. Terrestrial mammals have hair (hides).

Wool is excellent for thermal insulation. It has a higher spiral than a bristle and can incorporate more air. Aquatic mammals such as whales and seals, as well as some birds (penguins), have a special layer of insulating fat ("whale oil"), and their feathers and fur are no longer as warm in the water as they are on land.

But some mammals are not strictly homeothermic, for example, during hibernation, their body temperature drops by 10°C or more. In this way, they can conserve energy and survive months of harsh winter with little or no food (in an occasional state of awakening). Such as hedgehogs and hibernating rats.

Some insects also have a tendency to be homeothermic, such as bees being able to keep the temperature of the hive roughly constant by shaking their muscles when it is cold outside. But this constant temperature is not for the individual, but for the entire colony. Hummingbirds, platypus, large insects, and fish are called cold-blooded (ectotherms) and their body temperature is not constant, but to some extent it is metabolically regulated.

In fact, there are also homeothermic plants, such as the stinky woad, which can maintain a body temperature of 20 degrees Celsius in an environment below 0 degrees Celsius outside, and the heat is generated through the mitochondria of the flower branches.

ectotherms. Fish, amphibians and reptiles, etc., because there is no specific temperature regulation mechanism, so the body temperature is not easy to maintain a certain and will change with the change of the environment, called ectotherms, also known as ectotherms, which means that the body temperature comes from the outside world. These animals not only have a lower metabolic rate, but also have poor thermal insulation in their bodies.

Therefore, the maintenance of body temperature does not depend on the energy obtained by metabolism.

Ectotherms usually adapt to their environment by adjusting their behavior when the outside temperature changes, rather than being at the mercy of the environment. This pattern of behavior is called behavioral thermoregulation. For example, lizards move around looking for a warm place to live; Exposure to the sun with maximum body surface area when necessary to absorb infrared heat; or by conducting heat by relying on a hot rock.