Now reptiles such as snakes, lizards, etc., in the cold winter comes, mostly to cease their activities, have plunged into the underground caves, eat or drink, do not move, Shuiqi great feel. This perception sleep I could go on a long sleep coming warmth of spring has been only revived again come back to open water cut-off. Reptiles are cold-blooded animal, commonly known as cold-blooded animals. Of their relatively low levels of the body's metabolism, producing less heat, coupled with body surface did not like the feathers of birds, mammals, as the thermal insulation of the hair structure, it is not a constant body temperature may rise as the temperature changes in the external environment changes . When the ambient temperature is too high or too low will affect their normal life. Only suitable for external temperature, the temperature in the most suitable condition, will they be agile, lively, four feeding, breeding future generations. . In contrast, mammals and birds, because they have a perfect body temperature regulation mechanism, with a high level of metabolism, the body can produce more heat to warm themselves, and through the body surface of the hair, feathers for insulation, through sweat evaporation and exhaled heat and other forms to distribute excess heat - cooling, so temperature can be maintained relatively stable, free from the external environment the impact of hot and cold. Therefore, mammals and birds are warm-blooded. Into the winter, temperatures slowly lower the body temperature of reptiles is also decreased, metabolism slowed down and finally penetrate into the cave, relying on weak geothermal and low metabolism sustain life. Hibernating reptiles from the cold to the injury, it is a poor low temperature adaptation. In the Mesozoic Era, known as the king of the dinosaurs reptiles is also need to hibernate it? The answer should be negative. Imagine, a few meters, tens of meters long and weighs several tons, dozens of tons of dinosaur can penetrate into the ground do hibernation? It is clearly impossible! If unable to penetrate into the cave, but do not eat not move to sleep on the ground, forming lying dead silence everywhere scenery do this not funny? The ancient geography, ancient climate data show that dinosaurs dominated the Mesozoic Era, the Earth's climate was warmer than the present number, there was no significant seasonal changes, there is no significant temperature difference between day and night, north and south poles of the temperature much higher than it is now, there is no cold the world a warmer. In the wilderness on toward flat, rivers, lakes broad cloth, Pine, cycads, ginkgo and other gymnosperms covered with vast land is green everywhere in the world with one of the wonderful vibrant scene. Dinosaurs that live in such a warm, but the prehistoric environment of adequate food, there is no cold, they do not need hibernation.