There are two small protrusions moving on the calm river surface, which generally do not attract people's attention, but do not underestimate them, it is likely that under the small protrusions is the "cold-blooded killer" - crocodiles, which are the largest reptiles in existence.
They are covered in scales and have great strength, which can be described as the "King of wet lands". Crocodiles are the largest and most dangerous reptiles in the world. They often lurk in the water or by mud ponds, waiting for their prey to arrive.
Crocodiles mostly live in the tropics and a few temperate regions, warming up in the sun during the day and returning to warm water at night. The crocodile's "waterproof device" is very unique: the mouth and throat are separated by a kind of bony fold covering the jaw, the ear achum is closed tightly, the trapdoor in the nostril closes automatically, and the eye is covered with a transparent eyelid, forming a good protective film.
Crocodile eyes grow higher on their heads, and when they dive into the water, they only show a pair of eyes to observe the movement around them. Crocodile fish eyes can see three-dimensional objects, there is a membrane behind the eyes, so that more light can be reflected in, so the crocodile's night vision is very good. When the crocodile hides in the water, it looks like a dead piece of wood or a rock, which is conducive to the prey casting a net. Crocodiles often choose to hide on the banks of rivers, ponds, slopes... In short, hunting is carried out where the hunt is prone to slip.
Crocodile kidneys have poor excretion function, and the salt in the body must be excreted by opening the salt glands located near the eyes. When the crocodile swallows, its mouth will squeeze the salt glands and shed "tears". Nile crocodiles are strictly based on age and sex in different groups that live together. In a group, it is often the largest male crocodile or the more aggressive crocodile that holds the leadership.
Nile crocodiles live mainly in lakes and rivers. They mainly sneak up on animals that go down to the river to drink water, and drag the hunting animals into the water, causing them to drown. The courtship performance of the Nile crocodile is very wonderful, and the male crocodile will guard a section of the river bank, roar loudly, and strictly prohibit other crocodiles from breaking in.
When the female is attracted to it and swims to this side, the male swung her body excitedly, shooting water from her nostrils into the sky. The bay crocodile is an extremely dangerous animal, weighing up to 1,000 kilograms, with a body length of six or seven meters, and a maximum length of 10 meters. Because the bay crocodile lives in the seawater, it is also known as the "saltwater crocodile". b. Crocodiles are ferocious in nature and will become more ferocious with age.
The Yangtze crocodile is a specialty of China, and they are also the only crocodile reptiles in China and belong to the national level of protected animals. Of all the crocodile species, only the Yangtze crocodile and the American Missy crocodile live in temperate zones, so in the cold winter, they have to go to underground caves to dormant. The cave of the Yangtze crocodile is very complex. The surrounding area is full of escape holes, and they are all hidden in the grass, and the cave passages are crisscrossed.
Inside the cave, there are many small rooms: there are sleeping rooms, there are usual rest rooms, and there are waterholes for bathing. The Ganges crocodile lives in the rivers of northern India, with a long and narrow mouth and unusually sharp teeth, which is conducive to fishing. Their main food is fish. Ganga crocodiles never attack humans, but eat dead bodies floating on the Ganges. The American alligator is the largest reptile in the Western Hemisphere.
They usually live in swamps with rivers, preying on all animals that can be subdued. Every summer, the depressions are filled with water, thus becoming a pleasure for crocodiles to play and play, so local people call these depressions "crocodile fish holes." When winter comes, alligators will choose shallow caves to hibernate, and the temperature in the caves is sometimes only about 0 °C.