Factamero_ on Instagram: "Domestic rats can birth up to 14 pups at once, typical litters are 8-12. The pups are born blind, deaf, and hairless at around 5-6 grams each. Rat milk is 12% fat, triple that of cow's milk. In three weeks the pups grow tenfold. The mother loses up to 30% of her body weight during lactation. Each pup claims a specific nipple on day one and finds it by scent. If there are more pups than nipples, the weakest get pushed out. Natural selection starts at the first feeding. V