Picking the wrong berry from a bush isn't so difficult. Ask me how I know. And, for my second encounter, don't think because you see an animal eating it, it's safe!

And onions are mildly toxic to cats and dogs. There is a lot less shared responses as to what is toxic or edible across species.

Basically every flavor compound in an herb or spice we eat is a poison directed at insects, microbes, or other creatures. (much less every medicinal or psychoactive compound found in nature)

Did you know birds do not have receptors for capsaicin? They can eat any pepper and it doesn't affect them. So if you see a bird snacking on a pepper that's red or greenish-yellow, wrinkly, and has a pointy end, well ... watch out