Dumbo Gene is a recessive trait,
meaning if you breed rats that carry the dumbo gene together then you'll get Dumbos.
The ears are large and round,
set low on the sides of the head.
The head is triangular when viewed from above.
Standard Ears are a Dominant trait.
The ears are set
high on the head and relatively smaller then Dumbos,
(Though some standards have larger ears due to selective breeding).
Standard eared rats are the most commonly seen ear type, and are every bit as sweet and cuddly as a Dumbo. The ear does NOT make the rat.