This is a 3-day-old rat baby. It has no hair, and its eyes and ears are sealed shut. One cannot tell its final color at this point. An experienced person can determine the gender and some features, such as rex coat and whether it is a dumbo rat or not. Rex babies have curly whiskers even at this age. Dumbo babies have ears that point downwards rather than back--a subtle difference, but possible to discern.
A trio of the little darlings. If you notice, the one on the left is the darkest, the center a medium shade, and the one on the right a bit lighter yet. It's very hard to predict color at this age, but there is a correlation between pigment in pinkies like these and their final color.
At this age, they can just barely crawl around a bit. They home in on the scent of their mother and her milk, and, like any baby, spend the majority of their time either sleeping or eating. They are completely dependent upon their mother's milk for food.
Here is Whitney's litter at age 11 days. The dark ones are self blacks, and the lighter ones are siamese.
In about 3 days, their eyes will open and they will begin to explore and play. They may be beginning to nibble solid foods at this point, but are almost entirely dependent upon their mother's milk still. It is possible to determine their color and markings at this point, of course.
Here, a velvety little siamese baby. One can begin to observe differences in size, activity level, and pigmentation in babies of this age which can be considered in determining which babies might be the best to keep for breeding, if such is desired.
This baby, a capped/blazed agouti male, is about 14 days old and has just opened his eyes. He continues to need his mother's care to survive.
This baby, blue berkshire dumbo AR Bradlee, is about 17 days old. His fur is longer and he is more completely developed. He plays with his siblings, interacts with his mother, and even licks and grooms his human handler.
This baby, Russian Blue standard AR Before the Dawn, owned by Pat Whipple of Birch Hill Rattery, is also about 17 days old.