ratas

Rats are rodents of the genus Rattus, comprising several species that are among the most successful mammals. The two most familiar are the black rat (Rattus rattus) and the Norway rat (Rattus norvegicus). They are highly adaptable, omnivorous, and resilient, often living in close association with humans and thriving in urban environments worldwide.

Biology and behavior: Rats range about 20–40 cm in body length, with tails of similar length, and weigh roughly 150–500 g depending on species and sex. Their incisors continually grow, enabling gnawing. They are typically nocturnal, social, and vocalize and scent-mark as part of communication. Reproduction is rapid: gestation around 21–23 days, with litters of 6–12 and multiple litters per year.

Habitat, distribution, and ecology: Native to parts of Asia, rats spread globally through human activity, occupying sewers, buildings, fields, and docks. They are skilled climbers and swimmers and have omnivorous diets that include grains, fruits, garbage, and invertebrates. They can impact native ecosystems, particularly on islands, where they compete with or prey upon local fauna.

Human health and management: Rats are reservoirs for various pathogens and can transmit diseases such as leptospirosis and salmonellosis; fleas on rats have historically facilitated plague transmission. They cause crop and food losses and structural damage. Management typically emphasizes sanitation, exclusion, monitoring, and humane or ecologically informed control measures, with consideration given to non-target species and environmental impact.

Conservation status: Most widespread rat species are not endangered, though some island or endemic populations are threatened or extinct due to habitat loss and introduced predators. In many regions they are regarded as pests and the subject of control programs.