Rats are a diverse group of rodents found across the globe, inhabiting nearly every environment where humans reside. These adaptable creatures exhibit a wide spectrum of coat colors, ranging from various shades of brown and gray to striking white and even black.
Wild Rats That Are Black
Among wild rat populations, the presence of black coloration is primarily associated with two species: the Roof Rat (Rattus rattus) and the Norway Rat (Rattus norvegicus). The Roof Rat frequently displays a sleek, dark black coat. This species is generally smaller and more slender than its Norway Rat counterpart, commonly found in elevated structures like attics and rafters.
While the Roof Rat is often black, Norway Rats can also exhibit black fur due to a genetic condition called melanism. Although Norway Rats are typically brown or gray, a melanistic individual will have an excess of dark pigment, resulting in a black appearance. These black Norway Rats are less common in the wild than their brown relatives but are not unheard of. Therefore, encountering a black rat in a wild setting does not automatically confirm it as a Roof Rat.
Black Varieties in Pet Rats
Domesticated rats, often referred to as “fancy rats,” are primarily descended from the Norway Rat and have been selectively bred for a vast array of coat colors and patterns. Black is a common and popular color among pet rat enthusiasts, appearing in numerous variations. These include solid black, where the entire body is uniformly dark, and black-eyed whites, which have white fur but retain dark eyes.
Breeders also produce black hooded rats, characterized by a black head and a stripe of black down the spine against a white body. These domesticated black rats are known for their docile temperaments and are distinct from their wild relatives.
Identifying Rat Species Beyond Color
Relying solely on color to identify a rat species can be misleading because both Roof Rats and Norway Rats can be black. Distinguishing between these common species requires observing several other physical characteristics. Norway Rats are generally larger and stockier, typically weighing 200 to 500 grams, with a robust build.
In contrast, Roof Rats are more slender, usually weighing 75 to 250 grams, and appear agile. A key differentiating feature is tail length: the Norway Rat’s tail is typically shorter than its head and body combined, while the Roof Rat’s tail is usually longer than its head and body. Furthermore, Norway Rats have smaller, thicker ears and a blunter snout, whereas Roof Rats possess larger, thinner ears and a more pointed snout.