My kid hasn’t breast fed since maybe about 3 or 4 months.. he’s 15 months now. Why does he all of a sudden tug at my nipples or rub on them and burry his face into my chest? He hasn’t done this in forever.. i don’t know what to do. I still produce and pump occasionally but he never gets any of it. He’s on a special nutrition drink. I could give him some but I haven’t.. anybody know what this is? He’s been doing it on and off for about 2 months now.