There are 1500-2000 different documented rodent species.Rats and mice are most wide spread pests that not only causes nuisance but also spread epidemics and diseases.
Rodent management involve two stage process
Rodents can enter a building through any hole whether of sewer or a hole left for electrical wiring.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.
Rodent Proofing To stop rodents from entering is to seal all cracks holes, openings under doors, building foundation, vents etc. Do not use plastic sheeting, wood, or any material the rodents could gnaw through. Make sure doors, windows, and screens fit tightly. If not, cover the edges with sheet metal to prevent gnawing. Because rodents are excellent climbers, you must also seal any openings above ground level.