What does an adult domestic rat look like? - briefly
Adult domestic rats are usually 7–10 inches (18–25 cm) long, have a naked tail about the same length, and weigh 300–500 g; their coats can be brown, black, white, or patterned.
What does an adult domestic rat look like? - in detail
Adult pet rats typically measure 20–25 cm in body length, not including the tail, and weigh between 300 and 500 g. The tail adds another 15–20 cm and is slender, hair‑less, and covered with fine scales that give it a slightly rough texture. Tail length is roughly equal to or slightly shorter than the body.
Fur varies among breeds. Common varieties display short, dense coats that lie flat against the skin; hairless strains have smooth, bare skin with a thin layer of fine hair on the face and feet. Color patterns include solid shades (black, white, brown, silver), agouti (banded hairs giving a speckled look), and piebald combinations of white with patches of another color. Coat health is indicated by a glossy sheen and absence of bald spots or excessive dandruff.
The head is rounded with a short, blunt muzzle. Eyes are large, dark, and positioned on the sides of the head, providing a wide field of vision. Ears are small, rounded, and covered with fine fur; they are highly mobile and respond to subtle sounds. Whiskers (vibrissae) extend from the snout and above the eyes, serving as tactile sensors.
Limbs are short and sturdy. Front feet possess four toes, each ending in a small, curved claw used for climbing and handling food. Hind feet have five toes with similarly curved claws. Muscular forearms enable precise manipulation of objects, while the hind limbs provide strong propulsion for rapid bursts of speed.
Sexual dimorphism is minimal in appearance. Males may have a slightly larger overall size and a more pronounced anogenital region, but fur color, texture, and body proportions are comparable between sexes. Reproductive status does not markedly alter external features.
Common health indicators include clear eyes, clean ears, a smooth tail without lesions, and a coat that repels dirt. Any swelling, discharge, or abnormal fur loss warrants veterinary examination.