Just a couple of months into their development, little humans begin peeing freely into the amniotic fluid that surrounds them in the womb. Then, foreshadowing all the gross stuff that babies do once they’re born, they’ll consume that urine as they swallow the amniotic fluid. Every last one of us has spent several months drinking our own pee. Yay.

In utero pooping is less common. Fetuses get their nutrients from food that their mothers’ digestive systems have broken down, and the waste from that food stays with mom and is taken care of on her end (Thanks, Mom!). Fetuses do ingest some stuff—mucus, bile, fine fetal hairs called lanugo, cells lining the inside of the womb—that needs to get disposed of, though. All this stuff gets broken down by the fetus’s digestive system and forms a viscous, sticky mass of feces called meconium, which is babies first poop.

@mrs.n2014, Reaaally. Thats pretty neat to know! Thank you.