Rats are common pests that infest and enter homes and office buildings in search of food or shelter. Though their evolution has helped them to live side by side with humans, they can cause harm to buildings and health. They were the most plausible cause of plague in many countries in the past. Moreover, they transmit a number of diseases due to their tendency to feed on garbage and move through the sewers. They can even cause a damage to the building by chewing home insulation, electrical wires and plaster walls. Their droppings are also a breeding ground for disease-causing organisms.