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Three lines of defense are critical in any rodent management program. The first line is at the perimeter or fence of the facility to intercept rodents entering a facility from an outside harborage. Harborages such as tall weeds and other vegetation should be removed. Tamper-resistant bait stations should be placed at regular intervals along the fence. The second line of defense is around the building perimeter, and bait stations should be placed at regular intervals. In addition, woodpiles, empty boxes, logs, etc., near the building perimeter should be removed. Lawns should be mowed. Thick shrubs and ivy and vine growth on the walls should be removed. Trees and shrubs should be pruned. All water leaks should be fixed to reduce a source of water. Trash cans and Dumpsters should be provided with tight lids and kept away from the building. The third line of defense begins with the building interior. All potential entry points like doors, vents, and pipes have to be sealed to exclude rodents.

Rodent proofing

Exclusion techniques or rodent proofing the building is the key to a successful rodent management program. Although total exclusion might not be possible due to the size or design of a facility, every effort must be directed to identify possible routes whereby rodents can enter the building.

Openings greater than ¼ inch for mouse and ½ inch for rats must be sealed. Hardware cloth, coarse steel wool, or mortar can be used for sealing purposes. A 12-inch metal plate should be attached to the outside of doors. Rodents should be prevented from climbing pipes outside the buildings by fitting metal guards around the pipes. The ultimate aim is to exclude rodents from entering the facility.

Proper sanitation is essential. This includes removal of trash and garbage piles, removal of grass, weeds and undesirable vegetation adjacent to buildings and elimination of potential rodent harborages. Proper storage practices that will permit regular cleaning and inspection are also important. It is necessary to practice good housekeeping that will limit areas where rodents can nest. Products should be placed on pallets, away from walls, so as to allow inspections, cleaning, and appropriate rodent management measures.

Trapping and rodenticides

Another important method of rodent management involves the use of traps and rodenticides. The home range for a rat is about 100 feet and that for a mouse is about 10 feet. This behavior should be taken into consideration when placing traps and bait stations. Traps and bait stations have to be placed every 8 to 12 feet for mice and 25 to 50 feet for rats. Trapping is one of the safest methods for managing rodents because it does not involve the use of toxic materials. Traps are useful in areas where poisoned baits cannot be used, especially inside the plant. Also, dead animals can be easily located and discarded. To be most effective traps should be placed along normal runways with the triggers of spring traps placed adjacent to walls. Traps also need to be checked more frequently. The most commonly used traps are snap traps. These are usually baited with peanut butter, although there are newer models with expanded triggers that do not require baiting. Glue boards or sticky traps can also be used in the same manner as snap traps. However, rats are more difficult to catch on glue boards because they are larger and stronger than mice. Automatic multiple catch traps or "Ketch-alls" are used to catch mice. There are two types of multiple catch traps — one uses a wind-up mechanism that throws the mice into a chamber, and the other uses a trap door principle.

Rodenticides can be classified into two main groups: anticoagulants and non-anticoagulants. Anticoagulant rodenticides cause rodents to die of internal bleeding. The poison disrupts the blood clotting mechanism of the animal. All anticoagulants are slow acting, and death may occur from three to 10 days after bait consumption. The older anticoagulant rodenticides required multiple feeding by rodents, whereas the newer ones require a single feeding. Non-anticoagulant rodenticides cause death of rodents in various ways. Most non-anticoagulants are single dose poisons.

Bait shyness and resistance to rodenticides may sometimes be encountered. Baits must be fresh and attractive to the target rodents. Prebaiting with a non-toxic food source may sometimes be necessary to overcome bait shyness, and also to monitor rodent activity. However, all other competing food sources must be eliminated. Liquid baits may prove more effective in managing rodent populations in areas where water is a limiting factor. Tracking powders (rodenticides in powder form) are often used when baits are not well accepted or where food is abundant. These are usually blown into rodent burrows or wall voids. The rodents pick up the dust and ingest the toxicant while grooming themselves. Fumigation of rodent burrows is an effective rodent management method. However, only licensed and trained professionals or applicators should carry out fumigation of rodent burrows.

Poisoning and trapping will reduce rodent populations as long as they are used. Once these efforts are stopped or reduced, the rodent populations build up rapidly. Rodent populations cannot be completely eradicated. However, populations can be brought down to a level where they do not cause aesthetic or economic damage.