Rex is a hair type, that looks kinda kinky or curly, a rex will have curly whiskers... there are also double rex who look just like a rex, other than thier hair seems a bit shorter and sparse. Rex rats do not lose thier hair, however, double rex, which is often mistaken for a nekkid (hairless) rat do lose thier hair in patches through out most of the yr, and it grows back whenever, the patches appear at irregular intervals. Double rex has also been referred to as a Patch~Work by some relatively new breeders that think they have "something new and different genetically than a double rex" when indeed it is truelly a double rex. A true Nekkid (hairless) rat, is just that...has no hair, not even peach fuzz, it is truelly nekkid, void of hair.Originally Posted by gmmuscle91