rato

Rato is the common name for various medium-sized rodents in the genus Rattus, within the family Muridae. The best known species are the brown rat (Rattus norvegicus) and the black rat (Rattus rattus). Both are native to Asia but have spread worldwide through human activity, and they are now among the most widespread mammal species in urban and rural areas.

Description and biology: Rats are typically 15 to 25 cm long with tails of similar length. Adults of the brown rat usually weigh between 200 and 500 grams, while physical characteristics vary by species. Fur color ranges from brown to grey, and their incisor teeth continually grow, requiring gnawing to keep them worn down. They are highly adaptable, omnivorous feeders that consume cereals, fruits, garbage, and animal matter. They are excellent climbers and swimmers, and they build nests in burrows, walls, and sewer systems.

Habitat and distribution: Rats inhabit a wide range of environments, from urban centers to rural farms. They prefer places with food sources and shelter, and they are especially successful in proximity to humans. Their cosmopolitan distribution is largely the result of international trade, shipping, and settlement.

Behavior and reproduction: Rats are mostly nocturnal and social, living in groups with complex social structures. Breeding can occur year-round in favorable conditions; gestation is about 21–23 days, with litter sizes commonly ranging from 6 to 12 pups. They reach sexual maturity quickly, leading to rapid population growth.

Impact and use: Rats are often regarded as pests due to damage to food, property, and infrastructure, and they can transmit diseases such as leptospirosis and salmonellosis; historically, fleas on rats facilitated plague transmission. Conversely, the laboratory rat, Rattus norvegicus, is a major model organism in biomedical research, contributing to neuroscience, physiology, and genetics.