Rattus rattus, commonly known as the black rat or ship rat, is a medium-sized rodent that has played a significant role in human history. Originally native to South Asia, this species has spread globally, often found in urban and rural environments. Adults typically measure about 16 to 24 centimeters (6 to 9 inches) in body length, with long, slender tails that can exceed their body length. Their fur is generally dark gray or black, with lighter underparts.

Black rats are highly adaptable, thriving in diverse habitats, including homes, warehouses, and agricultural areas. They are primarily nocturnal and are known for their agility, which allows them to climb and jump effectively. Their diet is omnivorous, consisting of fruits, grains, and small insects, making them opportunistic feeders.

Reproductive rates in Rattus rattus are high, with females capable of producing several litters each year, contributing to their status as common pests. They are also known carriers of diseases, including leptospirosis and hantavirus, posing health risks to humans. Despite their negative reputation, black rats have played crucial roles in ecological systems as prey for various predators. Understanding their behavior and impact is essential for effective management and control strategies.