Gerbils are not rats, but rather distinct species of small rodents. While both animals belong to the broad order Rodentia, meaning they share common characteristics like continuously growing incisors, they diverge significantly in their biological classification. Despite some superficial similarities in appearance as small mammals, gerbils and rats occupy different branches of the rodent family tree.
Gerbil vs. Rat: A Comparative Look
Gerbils and rats differ notably in physical characteristics; rats, such as the brown rat (Rattus norvegicus), are considerably larger, typically seven to eight inches long and weighing 350 to 650 grams. Gerbils, like the Mongolian gerbil (Meriones unguiculatus), are much smaller, usually four to six inches long and weighing 60 to 100 grams. A prominent distinction is their tail; gerbils have a long, furry tail for balance, while rats have a longer, mostly hairless, prehensile tail for gripping. Gerbils tend to have a slender body and often sit upright, resembling small wallabies, whereas rats are generally wider and lower-set. Some rat varieties display “dumbo” ears, set lower on the head, a trait not observed in gerbils.
Behavioral traits also distinguish these rodents; both are social animals that thrive in groups of their own species. Gerbils are quite particular about their social structures, making it challenging to introduce new adult animals into an existing group. Rats, conversely, are more adaptable to new introductions, though social hierarchies exist. Gerbils are active day and night (crepuscular or diurnal), while rats are primarily nocturnal. Gerbils are avid burrowers, creating intricate tunnel systems and requiring deep bedding, while rats are skilled climbers, benefiting from tall cages with vertical spaces.
The temperament and intelligence levels also vary between the two. Rats are frequently noted for their intelligence, trainability, and capacity to form strong, affectionate bonds with their owners, often compared to small dogs. Their dexterity also allows them to manipulate objects with ease. Gerbils are inquisitive and can be tamed, but they may be more skittish and generally less loyal than rats, though individual personalities differ.
Regarding care, gerbils typically have a lifespan of two to four years, with some species living up to eight years, while pet rats generally live for two to five years. Both are omnivores and benefit from a diet of commercial pellets, supplemented with fresh vegetables and fruits. Enclosure requirements reflect their natural behaviors; gerbils need tanks with substantial bedding for tunneling, while rats require spacious, multi-level barred cages to accommodate their climbing instincts.
Understanding Their Classification
Despite their shared classification within the order Rodentia, gerbils and rats belong to different taxonomic groups at lower levels, illustrating their biological distinctness. Both species are part of the class Mammalia and the order Rodentia, which encompasses all gnawing mammals characterized by a single pair of continuously growing incisors in both upper and lower jaws. However, their classifications diverge at the family level.
“True rats,” such as the brown rat (Rattus norvegicus) and the black rat (Rattus rattus), are members of the genus Rattus, which falls under the family Muridae. This family, Muridae, is one of the largest mammal families, including Old World mice and many rat species. Gerbils, conversely, are classified within the subfamily Gerbillinae. This subfamily is often considered part of the Muridae family as well, though some classifications place them within Cricetidae. The most common pet gerbil, the Mongolian gerbil, has the scientific name Meriones unguiculatus, belonging to the genus Meriones. Therefore, while both are rodents and may even share the broader Muridae family, they are distinct at the subfamily and genus levels, confirming they are separate species with different evolutionary paths and biological characteristics.