How do terrestrial animals adapt to the environment? First of all, the land climate is relatively dry, so the bodies of terrestrial animals generally have structures to prevent water loss. For example, snakes have scales, turtles have armor, and insects have exoskeletons. Secondly, terrestrial animals generally have organs to support their bodies and movements, which can be used for crawling (such as snakes), walking (such as camels), jumping (such as rabbits), running (such as cheetahs), climbing (such as golden monkeys) and other sports modes to feed and avoid enemies. In addition, most terrestrial animals have respiratory organs that can breathe in the air, such as rabbits, trachea and lungs, which can breathe. However, earthworms breathe in different ways. It depends on the body wall that can secrete mucus and keep it moist all the time. The oxygen in the air should first dissolve in the mucus on the body surface, then penetrate into the body wall and then enter the capillaries on the body wall. Just now, we also mentioned that terrestrial animals avoid the enemy. They can avoid enemies mainly because terrestrial animals have developed senses and nervous systems. Take the rabbit as an example, its developed brain, nerves all over the body and developed limbs can sensitively perceive the changes of the external environment and respond to the changing environment in time. The body structure of terrestrial animals is also very important. Earthworms can't keep a constant body temperature because of their flexible body movements, and they can only live in deep soil with little temperature change. But the rabbit's body hair is smooth and soft, which has the function of heat preservation. Its respiratory system and circulatory system provide enough energy for the body to keep the rabbit's body temperature unchanged from the outside world. The digestive system of terrestrial animals is also very special. Rabbit teeth are divided into incisors and molars. Incisors are suitable for cutting plant fibers, and molars are suitable for grinding food. The rabbit has grown a cecum. These structures are adapted to its habit of eating plants. In addition to incisors and molars, mammals such as wolves and tigers also have sharp canine teeth, which can be used to tear food. This is my own answer, combined with other people's dry land climate, in line with this, terrestrial animals generally have a structure to prevent water loss. Animals on land are not affected by the buoyancy of water, and generally have organs to support their bodies and movements, which are used for crawling, walking, jumping, running, climbing and other sports in order to feed and avoid enemies. In addition to earthworms and other animals, animals living on land generally have various respiratory organs that can breathe air and are located inside their bodies. Land animals usually have developed sensory organs and nervous systems, which can respond to changing environment in time. The appearance of fluffy eggs solves the problem of water shortage on land, allows eggs to hatch in a stable environment and the evolution of bones. The appearance of five-toed appendages solved the gravity problem of walking on land, retained water through the reabsorption of kidneys, and the appearance of cuticle water-retaining lung solved the problem of breathing. Gas exchange in the body can reduce the water loss caused by breathing, mainly to solve the change of gas exchange medium, the disappearance of buoyancy and the reduction of water. There are many kinds of mammals, but the relationship between mammals and the external environment is extremely complicated. Water, climate, light, temperature, humidity and other factors are all important limiting factors for the life and survival of mammals. The morphological structure and living habits of different kinds of mammals show their adaptation to various environments. Whole-body coat is an effective way for mammals to adapt to the environment, because the coat is lifeless, will not be burned by solar radiation, and can also play a role in heat insulation, so that a temperature gradient is formed between the coat and the skin. Due to different habitats and seasons, the coat quality, composition and looseness of each species are also different. Many species also have the habit of molting in different seasons, usually once a year 1-2 times. In spring and autumn, most of them molt in an orderly way, usually starting from scratch, with short and thin hair in summer and long and dense hair in winter. The body surface is unevenly covered with hair. Generally exposed armpit, groin, scrotum, breast and other parts, like a transom, can regulate body temperature. Other species, such as whales and dolphins, have no hair or almost no hair. They either live in warm waters or have some specialized tissues, such as thick skin, which can insulate heat. When the surface temperature is very high, most rodents hide in underground caves to block the holes, and squirrels living in arid and desert areas also sleep in summer. Nocturnal animals, such as tarsiers and lazy monkeys, crawl on branches in ventilated and cool places, and wait until after dark, when the ground temperature drops and the humidity is high, they go to the ground or among trees to feed and comb, and start their nocturnal life. Many mammals have a well-developed central nervous system, so they can choose their habitats accurately. If in summer, when the temperature in the area where he lives is very high, in order to avoid direct sunlight, he will go to the depths of the shade or the river to rest, stretch his body so that his abdomen is close to the ground, so as to use the wet surface to dissipate heat. He can also go to the river or pond for a long time for soaking, water bath or mud bath. On the other hand, aquatic mammals immerse their whole bodies in water and radiate their body temperature with their heads facing the flowing water. Among mammals, cloven-hoofed animals and some carnivores have no sweat glands. When the temperature is high in summer, I always squat in the shade and stick out my tongue to catch my breath to radiate my body temperature. When running, regulate your body temperature by breathing and temporarily storing residual heat in your body. Others use a lot of saliva instead of sweating to dissipate heat. Arctic foxes and polar bears live in the Arctic region. Their fur is very rich and has a good effect on keeping body temperature, so they can effectively resist the cold in the Arctic. Pinnipeds such as seals also live in polar cold waters. They rely on fur and subcutaneous fat to keep warm. Their skin cells also have strong adaptability to cold and can maintain normal life activities at low temperatures. Some species have local abnormal temperatures. For example, the body surface temperature of dogs is much lower than its depth, especially the feet, legs, tail, ear tips, mouth and nose are lower than other parts of the body surface, which can reduce energy loss and become an adaptation to the cold environment, which is also a way for them to use heat energy economically. In addition, burrowing mammals such as rodents also have the significance of cold protection. Rodents, pigs, bats, etc. Also, gregarious ways are often adopted to greatly reduce each individual's demand for heat energy to help prevent colds. Bears, bats, squirrels, etc. Hibernate to resist the cold in winter.