How a lot of people go on about how beautiful it is, but don't seem to realize that it can be really cruel as well, at least in the eyes of humans.
Like honeybees getting their stingers ripped out, along with vital organs attached to the stinger, and dying afterwards.
And lion cubs starving to death when there is little food because the adults always eat first. But if only the cubs got to eat, the adults would starve to death and there would be no lions to care for them. So if the adults survive, it's like "meh, we can always make more". Also, if a male lion joins up with another pride that already has cubs, he'll murder them so he can later replace them with his own. Lions are terrible stepparents.
Or water beetles that kill and eat other bugs or even small fish by stabbing them with their harpoon-like proboscis, injecting a liquid that turns the prey's innards to goo, and then drinking it up like a milkshake.
Not too long ago I saw a young penguin on TV starting to swim for the first time, only to be savagely killed and eaten by a leopard seal. Not fun to watch.