This article is from the Summer 2003 AFRMA Rat & Mouse Tales news-magazine.
Colors & Coats
By Nichole Royer
Kerri, Roseburg, OR, e-mail
Q I am trying to breed Chocolate self rats. If you have one for sale or can tell me what colors to breed together, I’d appreciate it.
Cocoa (L), Chocolate (middle & upper R), and Cocoa Satin (R) baby rats.
A Chocolate is an interesting color, and very beautiful. Like a deep dark milk chocolate. Unfortunately, it is not a color you can create by breeding two other colors together.
The color is caused by the “b” (brown) gene. It causes the black pigment in a rat’s coat to be diluted to that very pretty dark brown. It is a simple recessive gene, so a rat has to inherit it from both parents in order to be a Chocolate. For instance, most rats are “BB,” they do not carry Chocolate. Some rats have one Chocolate parent, and so are “Bb.” These rats are not Chocolate, but can have Chocolate babies. Thus, in order to breed Chocolate rats you have to get your hands on one in the first place. That rat can then be bred to another Self (a really good Black Self would be the best candidate). All their offspring will be Black, but if you breed them together or back to the Chocolate parent, you will get more Chocolates.
One of the problems with Chocolate is that a badly colored adult Black will sometimes mimic the appearance of a badly colored Chocolate. It’s not unusual for Blacks who have not been bred for good color to “rust” and turn a patchy brown. Rarely do these end up being true Chocolates, and even if they were, their very poor color would make them a bad choice for use in a breeding program.
As youngsters, the Chocolate color is always the most obvious. It’s a beautiful, even dark brown, very distinct from even the very worst of the poorly colored Black kittens.
Due to the time and effort involved, however, I do not ship. Done the safe and legal way, shipping even one rat costs several hundred dollars, involves special shipping containers, vet certificates, and a trip to the airport.