When we get back from Daytona, my next project is to get two nice young female rats and raise them a little bit before getting a male.

When I was in PetSmart yesterday, picking up cat & dog food, and kitty litter, I noticed that they had female blue rats (I think that's what they called them, I remember at least blue - female and rat! LOL)

But they were $9.99 as opposed to their other female rats that were $6.99.

Are they any hardier than other rat females, or just more highly desired for coloring? I couldn't see them, they were all inside their igloos and since I wasn't buying yesterday, didn't ask them to pull them out.