Humans drink human milk, and the milk of other animals. Animals drink the milk of their own species on a regular basis. I will never understand why people get hung up on this in Zootopia as if drinking the milk of other creatures OR the same species is something humans and animals don’t ever do in real life.
Don’t you know you’re supposed to dissect every single frame of a movie, so you can point out all of the inaccuracies and vaguely relevant plot holes!