The four evils now refer to what the four are capable of transmitting

The current four pests refer to mosquitoes, flies, rats, and cockroaches, and these four organisms can transmit various infectious diseases and are harmful organisms. A few decades ago, the four pests were "flies, mosquitoes, rats, and sparrows", and later sparrows were "rehabilitated" and replaced by bed bugs. Later, due to changes in social life, bed bugs were replaced by cockroaches.

In 1960, after the eradication of sparrows, people painfully realized that although sparrows eat grain seeds, they also eat many pests. At that time, the locust population increased so much that China had to import sparrows from the Soviet Union.

Mosquitoes, flies, rats, and cockroaches often infest sewers, toilets, kitchens and other places with the most bacteria and viruses, and move back and forth between infected places and clean places, and their limbs, body hair, mouth, and stomach carry to easily spread pathogenic bacteria.

There are 252 kinds of pathogens such as germs, viruses, spirochetes, and rickettsials found in the world, of which 114 kinds can be carried by the "four pests".

Mosquitoes, flies, rats, cockroaches.

On February 12, 1958, the Communist Party of China issued the "Instructions on Eliminating the Four Evils and Stressing Health". It is proposed to complete the task of eliminating flies, mosquitoes, rats, and sparrows in one year or less.

Gradually, the sparrows were "rehabilitated" and replaced by bed bugs. Later, due to changes in social life, bed bugs were replaced by mantises. Therefore, the "four pests" were eventually identified as flies, mosquitoes, rats, and mantises.

The four pests include flies, mosquitoes, rats, and cockroaches.

The harm of the four evils:

1. Flies: Flies breed and fly among garbage, manure pits, toilets, rotting animal carcasses, pus, blood, sputum and vomit, and feed on them. It carries tens of thousands of bacteria, viruses and parasite eggs on its body and abdomen.

Flies have the habit of eating, spitting and pulling, and it flies down to **, ** food will be contaminated by bacteria, viruses, and eggs, and when people eat contaminated food or use contaminated eating utensils, intestinal infectious diseases can occur into parasitic diseases.

2. Mosquitoes: Mosquitoes have blood-sucking habits, looking for human or animal amino acids when sucking blood, especially babies or ** delicate, mosquitoes can inject malaria parasites, filarial larvae, Japanese encephalitis virus and other saliva into the human body with saliva to make people infected with the disease, therefore, mosquitoes not only bite people to suck blood and affect sleep, but also transmit Japanese encephalitis, malaria, dengue fever, filariasis, etc.

3. Rats: The harm of rats is well known, it not only steals food, bites furniture, clothing, books and stationery, destroys buildings, bites off wires, etc., causing economic losses, and is the most serious in the "four pests", rats mainly spread plague, leptospirosis, lambiasis, epidemic hemorrhagic fever, endemic rash, typhoid fever and other infectious diseases through their ectoparasites (rat lice) bites and blood sucking or their excrement pollution.

4. Cockroaches: Cockroaches often crawl in toilets and garbage cans, sucking dirt, and their bodies are covered with bacteria, viruses and parasite eggs, and they also like to forage on people's food and leftovers, so that the utensils and food are contaminated, which can cause infectious diseases such as hepatitis A, dysentery, typhoid fever, cholera, or bacterial food poisoning, as well as parasitic diseases such as roundworms and hookworms.

In recent years, cockroaches have also been found to cause allergic rhinitis, bronchial asthma and other allergic diseases in some people.

Flies, mosquitoes, rats, macaques.

Among them, macaques are the most serious, biting and hurting people, eating small birds and stealing bird eggs, reproducing quickly, destroying vegetation on a large scale, and must be completely killed.