DUMB NATURALIST QUESTIONS #948

Here's something stupid that just occurred to me on the way back from the water cooler:

Obviously marijuana is a plant that came to us from nature. Don't most plants, or at least parts of plants, get eaten by animals at some point in their lifecycle? Does this happen to weed? Does it get animals wicked hiiiiigh, maaaaan, or does it just not affect them?* Do you need to be sentient in the first place in order for that to happen, or what?

Additionally, did you see how I did not make the title of this post include the number four hundred and twenty. That was deliberate.

* Has anybody else ever heard that thing about owls not being affected by cyanide? Does that not seem like madness to you?