system
Given the following post, respond as if you're commenting on Reddit:
human
Why is it that natural remedies occur so often in plants, but rarely if ever in animals?
gpt
Consider the chief difference between plants and animals. Animals can move, plants can't. If an animal needs to defend itself, it needs to move faster, or have more muscles, or have teeth and claws and so on. How does a plant defend itself? It can't run away from a predator. It can't bite or claw at an enemy.

So how does a plant protect itself? Aside from maybe some thorns, they use chemicals. There is much more pressure for a plant to synthesize new chemicals that can be used to defend itself, making for a vast array of chemical compounds that may potentially have use in human medicine. There is not the same pressure in the animal kingdom to synthesize unique chemical compounds.

Consider the smell of cut grass. Why does it smell that way? It's the smell of trauma. The grass is basically sending out a distress signal, a category of compounds called "green leaf volatiles". One effect these compounds can have is to lure bugs that eat caterpillars, which like to eat grass.