How to tell if a baby rat is dumbo eared

Dumbo Rats are the same breed as fancy rats, they are just a different variety with a different type of ear. There are alot of rumors out there about dumbos being larger, gentler, sweeter, etc... but in truth these are nothing more then anecdotal rumors. I imagine it is because the dumbo ears do give rats a sweeter look to their face.

I admit dumbos are my absolute favorite. Their little faces make me melt.

To be a dumbo, rats need to have their ears set low on the sides of their head. The ears are often large and rounded.

Dumbo is a recessive trait. So it can be carried without showing up. In order to breed dumbos you need both parents to carry it.
If both parents are dumbos, u will get a litter of all dumbos.
If you have a dumbo parent & a standard eared parent but the standard eared parent carries dumbo, then you can have like a quarter of your babies be dumbo.
If the standard eared parent does not carry dumbo then all of the babies will be standard eared.

http://www.afrma.org/ratvar.htm#dumbo

In baby rats you can tell if it will be dumbo by checking the angle & location of the ear. If the top of the ear lines up with the middle of the eye, then it is dumbo!