It's funny how parenting can differ among species. If you saw a woman in a park somewhere forcing her infant daughter to roll around in mud, you probably would be appalled. You might even call Child Protective Services. But for rhinoceroses, the opposite is true. Wallowing in mud is just part of being a rhino, and every rhino calf has to learn how to do it properly. Teaching a baby rhino how to get down and get filthy is a mother's duty. You'd be a terrible rhino mom if your child wasn't covered in mud.