Cats, belonging to cats, are divided into domestic cats and wild cats, and are widely used pets in families all over the world.
Rats are mammals, rodents, rodents, commonly known as "rats", which are the fastest-reproducing and highly viable animals among mammals.
Appearance characteristics:
1, a general term for rodents and rodents. Small in size, the body color is mainly gray and brown. There are a pair of incisors in the upper jaw and lower jaw, and most of them have no teeth ... Mice mature sexually early and usually begin to reproduce a few months after birth. It can breed several times a year and give birth to about ten cubs at a time. Strong adaptability, wide distribution and many kinds.
2. According to statistics, there are about 480 species of rodents in the world and 34 species in China. ? [ 1]? Its main characteristics are that its body is conical, without canine teeth, there is a gap between incisors and premolars or molars, incisors are developed, rootless, life-long growth, and ordinary teeth are shortened; Act quickly; Plants are staple food, and some are omnivorous; There are many kinds. The mouse is a kind of rodent, and its size is large and small.
There are many kinds of mice, there are more than 450 kinds in the world. Mouse is one of the most primitive mammals in existence. They are energetic, numerous, extremely fast in reproduction and adaptable. They can eat almost anything and live anywhere. Rats can dig holes, climb trees and spread diseases such as plague, epidemic hemorrhagic fever and leptospirosis. However, mice provide countless experimental data of drugs.
Like human beings, mice also use facial expressions to express their discomfort. When they feel pain, their eyes will squint, their cheeks will bulge, their ears will fall back, and their beards will shrink or stand up. After injection of painkillers, all these expressions disappeared and returned to normal. Through experiments, researchers can determine the degree of pain represented by different facial expressions, which can be used to alleviate the pain of mice or other animals in future medical research.
Extended data morphological characteristics:
1, the cat's body is divided into five parts: head, neck, trunk, limbs and tail. Most parts are hairy, and a few are hairless cats.
The cat has a fat pad at the bottom of its toe, so it walks quietly. When catching a mouse, it won't run away, and there are sharp nails on its toes. Paws can be retracted and extended. Cats retract their claws when resting and walking, and only extend their claws when catching mice and climbing to prevent their nails from becoming dull. A cat has five fingers in its forelimbs and four fingers in its hind limbs. Cats' teeth are divided into incisors, canines and molars. Dog teeth are particularly developed, with sharp cones, which are suitable for killing caught mice. The chewing surface of molar teeth has sharp protrusions, which are suitable for chewing meat. Underdeveloped front teeth.
References:
Baidu Encyclopedia-Morphological Characteristics of Cats
References:
Baidu Encyclopedia-Mouse? Appearance characteristics