How Much Rats Are in the World
WouterRats are largely nocturnal animals, leaving their nests at dusk. They are highly adaptive and can survive in large numbers in new environments and with different food sources and routines. However, they can cause considerable damage to buildings and infrastructure. According to statistics, they caused $19 billion in economic damage in 2000.
Most species of rats are less than one inch long and weigh three to ten ounces, but some are much larger than this. The largest species, the Sumatran bamboo rat, can grow to be 20 inches long, including its tail, and weigh as much as eight pounds. The smallest species, the Gambian pouched rat, is a few inches shorter and has a tail about eight inches long.
Rats mate about five hundred times per year, and female rats can give birth to up to 2,000 offspring in a single year. Brown rats typically have eight to nine young at a time, while tropical rats can produce anywhere from one to six pups at a time. Interestingly, rats breed year round, but the majority of breeding occurs in spring and fall.
Rats are a problem throughout the world. They are common in urban areas, like Los Angeles, where police have even used feral cats to fight rats. Rats are also a problem in Washington, D.C., where a former morgue contractor reported that rats had attacked him. This has been an ongoing problem for decades.
