How can I keep Rats from nesting?
As a rule, anything that will make a structure less hospitable to rodents should be considered important. Along with sanitation, exclusion is the first line of defense against rodents. As rats can enter structures through ½-inch holes and mice through ¼-inch holes, every effort should be made to seal these exterior entry points. This can be done with ¼-inch mesh metal screen or hardware cloth, metal “wool” products, concrete mixes or durable sealants for smaller openings.
Where rodent activity is high, building construction should take into consideration the jumping and climbing abilities of rodents. Because rats can jump about three feet vertically, 3-½-foot bands of polished metal or gloss paint should extend up from grade level around the structure. To help prevent rodents from burrowing under the structure, a metal band should extend two feet below grade.
Often, rodents enter structures through doors. Doors should be kept closed, should clear floors by no more than ¼-inch and have metal kick plates attached to prevent rodents from gnawing on them. Twelve-inch metal collars can be attached to support poles, pillars and vertical pipes to prevent rodents from climbing them. Exterior vents and floor drains should be covered with screens or grates sufficient to exclude rodents, and spaces around drains should be filled with cement.
Sanitation and exclusion work together to enhance the effectiveness of trapping and baiting; all are components of an integrated rodent management program. Removing food sources and restricting rodent access forces rodents to roam farther away from their nests in search of food, making their contact with rodent traps and baits more likely.