A certain type of plant that makes its own poison to protect itself from tiny predators may be irritating to humans as well.
These plants, called nightshades, are grouped together because they contain chemical compounds called alkaloids including solanine, a natural insecticide. Some nightshades, such as belladonna, are toxic to animals and humans, but others—such as tomatoes, white potatoes, eggplant, and peppers—serve as nutritious foods common in diets around the world.





