This boy was born 1.5 months ago and he's not nearly as large as his half brothers, who are 2 weeks younger than him. I've never had a rat still small at this age in all my litters. I'm not familiar with dwarf genetics but thought I'd ask just in case. Sorry for the crappy pics lol
(also any guesses on the colour? he's got black eyes and was much darker colour when he was a baby, so I thought blue roan but he doesn't have strong ticking)