In the animal kingdom, there is nothing more scary than a mother that is protective over her kids. We already know from humans, but animals don’t follow laws. They do what their instincts tell them to do. Large birds such as geese and ducks are known to beat up human kids pretty badly for getting too close to their babies.
The problem occurs when you have aggressive protective large animals who can tear your head off with a single swipe. Not only that, but that animal can also outrun you. If you stumble onto a grizzly cub you better watch out, as the mother isn’t too far away. You better hope she’s in a good mood if you do.