Keeping your property free of rats and mice is a perpetual problem for home and property owners. New York City recently put noted rodentologist Bobby Corrigan on the payroll fulltime to combat its burgeoning rat problem. Heading a beefed-up squad of special inspectors known as the “Rat Pack,” Corrigan and his crew are patrolling the city to root out rodent infestations, visiting as many as 200 buildings a day. If cited, property owners have two weeks to evict the varmints or face a fine.
Eviction is rarely easy. Widespread and abundant, rats and mice are considered the second and third most successful mammalian species inhabiting Earth today. Only humans have proved more adaptable. Spread throughout the world by early seafarers, rats and mice are found on all Earth’s continents, exhibiting an amazing ability to adapt to extreme and harsh climate conditions. Rodents thrive in diverse environments from swampy river banks and city sewers to the upper branches of trees and the top floors of high-rise buildings. Opportunistic survivors that live with and near humans, Corrigan calls rats “a barometer for human activity.”
Rats and mice have long been a problem in large metropolitan areas where food sources and hiding places abound. The low shrubbery, parked cars, construction sites, abandoned buildings, tunnels and sewers common in cities provide ideal cover and harborage. Overflowing dumpsters, trash bags stacked along sidewalks and lunch bags tossed in sidewalk garbage cans provide a never-ending food source. But mice and rats are not relegated to cities. As natural habitats in fields, woods and rivers have given way to development, rodents increasingly seek harborage in suburban homes and multi-family dwellings. A recent History channel special, Life After People, postulated that without man’s refuse to feed on, rats and mice would be among the first animals to perish should man become extinct.
The challenge in keeping rodents out of a building is to find and seal off entry points. It’s narrow skull and flexible body allows rodents to creep into homes through small cracks, holes and crevices and along sewer and pipe outlets. It’s said that if a mouse can fit his nose in a hole, he can squirm his body through it. Adept climbers, they use their long tails for balance. While mice are quite small, often only an inch or two in length and weighing less than an ounce, rats grow to 5 or more inches in size and can weigh a pound or more.
Primarily nocturnal, rats and mice build nests of sticks and leaves or nest in burrows. They live in polygynous groups of multiple males and females, the females breeding throughout the year. A mature female can produce up to five litters a year of 6 to 12 pups. Young rodents reach maturity quickly and are capable of reproducing by 3 to 5 months of age. In the wild rodents generally live 6 months to a year but have been known to live up to four years in captivity.