– Having constantly protruding breasts is only a feature of humans (and we’re not sure when it evolved, because other primates don’t have that, so don’t necessarily give it to all Hominids, especially ones closer to Chimps and the like). Other mammals just develop their mammary tissue when actively producing milk.
– Having breasts at all is unique to primates! Mammary tissue develops differently in other mammals and while you might call them breasts, they don’t develop in the same anatomical location and thus, aren’t breasts.
– Not all mammals even have nipples – Monotremes like the platypus and the echidna do not, they just excrete milk through their skin
– To be completely honest with you milk is just ridiculously nutritious sweat? It’s actually kind of gross when you think about it too hard. It may have evolved to keep eggs moist.
– Non-Mammals shouldn’t have breasts at all. Don’t put them on lizards, don’t put them on birds, don’t put them on dinosaurs, don’t put them on crocodiles, don’t put them on frogs fish insects coral molluscs spiders whatever just, just don’t. Mammals are literally named for mammary tissue – the ability to produce milk is solely a mammal thing. We don’t know exactly when they evolved in the group that mammals evolved within (Synapsida), but we know that they don’t exist outside of it.
– I don’t really give a shit that you want to make the animal “female” because, believe it or not, that’s A) transphobic B) ridiculously stupid because all animals literally don’t have mammary tissue unless they’re actively lactating so they don’t require breasts to identify an animal as female, so why should you?
– I don’t give a shit that you find breasts sexy that your own dealio but you shouldn’t put fucking breasts on animals. Like, stop being so anthropocentric. Get over it.