What makes rats a pest
Rats feed on all kinds of food, including ours. And when they do, they contaminate our food with their urine and faeces. In this way, rats transmit diseases such as leptospirosis. The infamous Black Plague that caused millions of deaths in England and Europe was the result of the disease being spread by rats.
Rats carry fleas and mites on their bodies which also transmit diseases to humans through their bites. Moreover, rats have been known to bite humans. To prevent their front teeth (called incisors) from growing too long, rats need to gnaw constantly. This gnawing habit destroys household items. Buildings have gone up in flames because rats have gnawed through the insulation around electrical wires.
Rats are social animals and prefer to live in nests. Outdoors, their nests can be found in garbage dumps, in the ground, in drains and other areas where food and shelter are nearby. Indoors, they hide in wall and floor voids, roof voids and furniture. Although rats cannot see well, they have very sharp senses of smell, hearing and touch. They eat all types of food and search for food during the night. They are good climbers and jumpers.