Facts, Identification & Control
Rats are mammals of the genus Rattus. The most commonly encountered commensal rat species in Canada are the Norway rat (Rattus norvegicus), also known as brown rats, and the roof rat (Rattus rattus), or black rats. Distinctive characteristics primarily include coarse fur, protruding ears, and long tails. Rats are of significance because they not only transmit and spread disease-causing germs but also can cause structural and aesthetic damage to property and food losses. In addition, people generally react with negativity and revulsion upon encountering the small mammals. The rodents pose a severe pest problem throughout virtually all populated areas of the world, including Canada.
Appearance / Identification
The two rat species have different and distinct features. The roof rat is most recognizable because of its long tail which drags behind it as it moves. The tail is often longer than the rest of the body. The body measures about 41 cm in length, is slick and lean with brown to black fur, and weighs between 150 and 250 g. The ears and eyes are large with pointed snout. The Norway rat on the other hand is stocky, heavy body, short tail with the body measuring about 30 to 50 cm. Its eyes and ears are small with blunt snout. The body has brown or black colouring, though some species may appear gray or white, as well.
Rats are present in Europe, Asia, Africa, Australia, and the Americas. The widespread population shows no signs of decreasing. In fact, brown and black rats are both considered abundant and of least concern of endangerment or extinction. The highly adaptable animals thrive in areas where humans live and feed on any obtainable food sources, which greatly diversifies the available habitats for rats.
While specific eating habits may differ slightly between particular rat species, the rodents generally eat anything. As omnivores, rats adhere to a mixed diet consisting of grains, fruits, nuts, vegetables, and meat. However, the Norway rat has been shown to prefer foods high in fat content such as grease and meat. Meanwhile, roof rats prefer grains, nuts, seeds, and plant-based foods.
Life Cycle / Reproduction
Rats usually only live to about six months of age in the wild. They reach sexual maturity at around two to three months old. Pregnancies last between 20 and 30 days and typically result in 6 to 12 offspring. Though the rodents possess short lifespans, the rapid rate at which they reproduce, coupled with short gestation periods and large litter sizes, allows rats to continue as formidable pests.
Problems Caused by Rats
The gnawing and foraging behaviours of rats often lead to food and structural damages in homes. During the pursuit of nourishment and nesting areas, the rodents may leave smudge marks and droppings behind, as well. Many people find rats disgusting and/or frightening and react with horror upon seeing the pests. Rats very rarely bite but will do so if provoked or trapped. In addition, rats can transmit pathogens directly on their bodies, saliva, urine, droppings, or thorough vectors such as fleas and mites. The rodents infamously proliferated the Black Death, which led to the deaths of millions of people in the 14th century. Though the pests do not carry the plague today, the spread of disease by rats is still a serious cause for concern.
Detection /Signs of Infestation
Rats are often heard rustling, squeaking, or gnawing while in hiding. The constant gnawing of rats also leaves telltale damage, like teeth marks, on hard surfaces. Other signs of a rat infestation include droppings, footprints, nests, and the visible trails formed when the rodents travel the same path repeatedly while foraging for food.
While even the most thorough homeowners may still end up with rat infestations, implementing certain preventative measures greatly reduces the possibility of rodent problems. Keeping the home properly insulated is a crucial step to reduce points of entry for rats, while storing garbage in sealed containers makes the contents less attractive to the rodents. Homeowners should screen off windows and keep the protective coverings in good repair, as well. While a proactive approach can significantly reduce the risk of rat problems, infestations may sometimes occur regardless. Rat infestations should not be taken lightly and normally require the assistance of a pest control professional to properly resolve.
Rats in Attic
Rats in House
Rats in Walls