They live on the principle of commensalisms that is sharing the human life without any positive feedback except damages they give in return.
They can enter a commercial building through stocks imported/exported, cracks & crevices ,fields their natural habitat, damp areas, trashes, etc.
They can adapt any mode of entry to enter a building. They mostly prefer areas where they can find suitable environment of food, shelter, breeding, etc.
They can chew anything from papers to electrical wires. They spread diseases like plague, typhus, etc.
Types Of Rats