I didn't know my friends baby keeps crying when I hold him, I guess that's why
All babies can. Last month i was holdin a breastfed newborn she woke up and tried to nurse from me. it was akward but my friend was understanding.
All babies can tell if you have milk. I work in childcare with infants and when I have been pregnant or breastfeeding the babies will try to find it if they are breastfed.
Idk but I would assume its all babies. My mom told me that after she had my brother, when he was still really little, whenever she would hear a baby cry her breasts would leak. It's crazy how our bodies just know. So I would assume that the babies know too