What is a rat with a white belly called? - briefly
A rat with a white underside is commonly termed a white‑belly (or white‑bellied) rat; when the entire coat is pale, it is classified as an albino rat.
What is a rat with a white belly called? - in detail
Rats displaying a distinctly white ventral area are most commonly identified by a coat‑pattern designation rather than a separate species name. The primary classifications are:
• Albino – complete lack of pigment results in pink eyes, pink skin and an entirely white coat, including the belly.
• Dutch – a bicolor pattern where the dorsal side carries a darker colour (often black, brown or agouti) while the ventral side remains pure white, extending from the chest to the tail.
• Hooded – similar to the Dutch pattern, but the white area is limited to the head, throat and belly, forming a “hood” around the body.
• Leucistic – partial loss of pigment produces a white belly with otherwise normal coloration; eyes retain normal colour.
In laboratory and pet‑trade terminology, the white‑belly characteristic is described as a “white‑belly phenotype” or “white‑ventral pattern.” When the trait is linked to a genetic mutation that eliminates melanin production, the term “albino” is applied. For breeders, the Dutch pattern is the most frequently referenced descriptor for a rat whose belly is white while the back retains a contrasting hue.