Newborns are pink, deaf, blind and hairless. They are often called souplings because that is roughly what they look like. A healthy soupling is warm, plump and has a visible white band of milk in the belly for the first week. No milk band means they are not feeding. Week one: fuzz appears, ears unfold. Week two: fur fills in, eyes still shut, they start wobbling around the nest. Around day 12 to 16 the eyes open and they become extremely mobile. Week three: solid food, first proper mischief, the mother starts leaving the nest more. Week four: eating independently but still learning from her. Handle briefly and gently from a few days old, with clean hands, and only if the mother is relaxed about it. Short daily handling makes calmer, friendlier adults. Separate the boys from the girls at five weeks. Rats can breed far younger than people expect, and littermates are no exception.