What is a rex rat?

Rex rats are domesticated rats with a particularly curly coat. Both their fur and whiskers are curled, which gives young rex rats an especially woolly appearance.

The gene for rex coats is dominant in rats, meaning that a rat only needs one copy of the gene to have a curly coat. The gene affects the rate at which hair all over the body grows, not just the coat, causing the hair shaft to twist irregularly. Rats with two copies of the gene experience hair loss after their first hair shedding and are called patchwork or semi-hairless. Rats with one copy often experience a change in hair texture as they age and undergo molts, changing from soft and tightly kinked to rougher and wavier. Older rex rats often have thin or patchy coats.