The purpose of eliminating the four pests is to eliminate insects and animals that can bring all kinds of harmful bacteria to people's lives, so that people's lives can be cleaner and healthier. The four pests are flies, rats, cockroaches and mosquitoes that spread bacteria in summer, which are common in the south.

The significance of getting rid of the four pests are;

1. controlling the prevalence of many infectious diseases. In Yunnan, Gansu and other places in China, the spread of plague has always existed due to the large-scale breeding of mice, which poses a great threat to people's health and life. Due to the frequent activities of mice, the spread of epidemic hemorrhage and murine typhoid is also increasing, which seriously affects people's healthy life. In addition, flies and mosquitoes, which are common in summer, as well as cockroaches, which are easy to see all year round in the southern region, also bring scourges, tetanus and many other diseases to people, jeopardizing human health and affecting normal life. Therefore, it is an important task to strengthen the activities to eliminate the four harmful factors and reduce the occurrence of many diseases caused by bacterial transmission.

2. Protect agricultural production and promote economic construction. Worldwide, about one-fifth of agricultural production losses are due to rat feces. Rats can also damage buildings and cause destruction of forest and grassland vegetation. Industrial blackouts in cities can also occur because of mouse bites. Therefore, prevention of mice has been the focus of attention of various production units in the field of sanitation. Modern civilized society should first be a clean and hygienic society, eliminating the four major hazards and making the human living environment healthier and cleaner is a basic requirement.