Rats are rodents. Among nearly 1800 species of rodents in the world, there are more than 200 pathogens, and 80 ~ 90% of rodents play different roles in the process of spreading diseases. Among the pathogens transmitted by rodents, 12 kinds of bacteria, 3/kloc-0 kinds of viruses, 5 kinds of rickettsia and 7 kinds of parasites are known to cause human diseases. The main rodent-borne diseases in China are plague, epidemic hemorrhagic fever, leptospirosis, typhoid fever, rabbit fever, salmonella enteritis, tick-borne relapsing fever, pseudotuberculosis, forest encephalitis, rabies, scrub typhus, Q fever, leishmaniasis, schistosomiasis and trichinosis. According to statistics, throughout history, the number of people who died of rat-borne diseases in the world far exceeded the number who died directly in the war.

2. Harm to agriculture, animal husbandry and forestry

According to statistics, the loss caused by rodents to agriculture in the world is equivalent to the sum of the gross national product of the 25 poorest countries, and it can feed 200 million to 300 million people. Generally speaking, rodents in farmland can reduce grain production by about 5%. Farmland in China suffers hundreds of millions of acres every year. Rodents in grassland mainly destroy the yield and quality of grassland and film star grassland, and even degrade grassland. China also has hundreds of millions of acres of pasture every year. Rodents in forest areas steal tree seeds and bite the bark of young trees, which affects the emergence rate and survival rate. Millions of acres of forest are destroyed every year in China.

3. Harm to the industry.

The harm of rodents to industry and commerce is mainly to destroy power supply and communication, causing accidents. There have been power outages in factories in China, resulting in a loss as high as150,000 yuan. There are many accidents that cause losses of tens of thousands to hundreds of thousands of yuan. In China, rats have been recorded to affect the normal navigation of ships and planes, and passengers are often harassed on trains.

4. Other dangers

The main harm of house mice is the spread of diseases, but stealing food and harassment can not be ignored. In rural areas, the grain wasted by each household sometimes reaches100 ~150kg every year. Rodents outside hotels and hospitals, etc. Sometimes it will have a bad effect.