Plants make poisons to stop animals from eating them, because if they get eaten, they die.

Plants produce a variety of natural chemical compounds as defensive mechanisms against herbivores and pathogens.

Plants make a wide variety of natural chemicals—like bitter toxins and sticky resins—that make them taste bad or even poison bugs that try to eat them.

The plant kingdom produces approximately one million distinct secondary metabolites with documented mammalian toxicity, and the vast majority of plant species contain at least one lethal compound at sufficient dosage.