Well, not quite. Rat stories are like fish stories, they get bigger with the passing of time. In fact, a large rat would weigh about 500gms (1lb) and be 45cm (17 in) long from nose to tip of tail.The common rat in Ontario is the Norway rat which is also called the brown, wharf or sewer rat. It does not come from Norway but originated in Asia. Rats were spread throughout the world on the early sailing ships. These are the largest and most common of the commensal rodents found in North America.Norway rats are usually brown with lighter coloured undersides but can vary through all shades from white to black. They are heavy bodied with blunt muzzles and small eyes and ears. These rats prefer to live in burrows in the ground but can also be found living in attics or in walls. Houses with dirt basements or crawl spaces provide an ideal site. Norway rats have poor eye sight but well developed senses of hearing, smell, taste and touch. They are not able to throw up which is one reason why they are weary of new or different foods. They are good at climbing, jumping and swimming. Females average 7-8 young per litter with 3-6 litters per year. Their life span in the wild is 6-12 months.Rats are more common than most people realize. They not only are found in agricultural, industrial and food processing operations but they frequently show up at garbage bins, compost piles and bird feeders in and around homes. I was once called to a home where we estimated a population of over 300 rats living in the back yard and feeding from the bird feeders. They would come right up and feed out of your hand. The homeowners had had them for years but claimed they didn’t know what they were. One estimate is that there are about 3 billion rats in the world today. Signs of rats include gnaw marks, droppings, tracks, rub or grease marks, burrows and runways. Rats are nocturnal and very cautious, and will shy away from new objects or changes in their environment.Adult rats are much larger than mice and have blunt rather than pointed noses. Their tails are shorter compared to their body size than mice. Young rats can be distinguished from mice by having larger heads and smaller ears. Rat droppings are thicker and rounded at both ends whereas mouse droppings tend to be thin and pointed at each end.
Controlling rats starts with improving sanitation, eliminating harborage sites and rat proofing. Rats will readily gnaw through wood and plastic and have been known to gnaw through lead pipes and uncured cement. Trapping works, but rats can become trap shy and will then avoid traps. Rodenticides are effective against rats but great care must be taken with dogs as they will readily eat the baits.
As a last resort, if all else has failed, Pied Pipers are said to be effective but make sure you pay him.
Dr. Bug - Urban Pest Control Ltd. 