Sanitation is fundamental to rat control and must be continuous. If sanitation measures are not properly maintained, the benefits of other measures will be lost, and rats will quickly return. Good housekeeping in and around buildings will reduce available shelter and food sources for Norway and, to some extent, roof rats.

Neat, off-the-ground storage of pipes, lumber, firewood, crates, boxes, gardening equipment, and other household goods will help reduce the suitability of the area for rats and will also make their detection easier.

Garbage, trash, and garden debris should be collected frequently, and all garbage receptacles should have tight-fitting covers. Where dogs are kept and fed outdoors, rats may become a problem if there is a ready supply of dog food. Feed your pet only the amount of food it will eat at a feeding, and store pet food in rodent-proof containers.

Seal cracks and openings in building foundations, and any openings for water pipes, electric wires, sewer pipes, drain spouts, and vents. No hole larger than 1/4 inch should be left unsealed to exclude both rats and house mice. Make sure doors, windows, and screens fit tightly. Their edges can be covered with sheet metal if gnawing is a problem. Coarse steel wool, wire screen, and lightweight sheet metal are excellent materials for plugging gaps and holes. Plastic sheeting, wood, caulking, and other less sturdy materials are likely to be gnawed away.

Excellent climbers. Can be found in cultivated fields, at or below ground level, or in upper stories of skyscrapers. Mice explore their limited home range of less than 30 feet daily for newly introduced objects. Nocturnal. Most activity and feeding takes place between a half hour after sunset and a half hour before sunrise. Strong social hierarchy. Able to swim.

Alexandrian rat, black rat, fruit rat and ship rat.

Able to swim, jump and climb, roof rats usually enter and nest in upper portions of buildings. May nest outside in trees (especially palm), ivy and similar vegetation. Burrow very little. Nocturnal. Most activity and feeding takes place between a half hour after sunset and a half hour before sunrise. Strong social hierarchy.

Brown rat, gray rat, common rat, house rat, wharf rat, sewer rat, barn rat and water rat.

Norway rats burrow extensively in soil and are excellent swimmers and good climbers. They usually nest in basements and lower portions of buildings. Nocturnal. Most activity and feeding takes place between a half hour after sunset and a half hour before sunrise. Very strong social hierarchy- the biggest and strongestNorway rats get the best food and harborage.