Let's not forget about line bred traits that are sort of heritable.

Not enough is known about the hypomelanism in False Water Cobras but that seems to be both genetic and line bred, or co-dom, or what have you.

It's easy to do a punnet square for one or two or maybe even three or four traits, but far more than those tiny numbers are in the mix.

I've bred blues to blue hooded and gotten no blue anythings. Odds, yes I know, but it really shouldn't work that way.

One of the things I really like about breeding the rats is the surprises you get.