How Plants Fight Back Against Predators

Plants don't have the luxury of being able to run, swim, or fly away when confronted with a predator. Instead, they've developed a repertoire of defense mechanisms for warding off threats while staying rooted to the ground.

As TED-Ed points out in a new video lesson by molecular biologist Valentin Hammoudi, some protective adaptations in plants are obvious, like the thorns on a rose or the spines on a cactus. Others are less apparent at first glance. The Van Houtte's columbine in Northern California, for example, is covered in tiny, sticky hairs called trichomes that are hard for humans to see. But when hungry bugs come near, lured in by the plant's enticing chemical scent, the hairs act like flypaper and trap them until they starve.

Then there's Mimosa pudica, which deploys a defense tactic that's invisible but impossible to ignore if you're standing in its immediate vicinity. When its roots are disturbed, the plant releases an odor that smells like, in the words of one researcher, "someone has broken wind."

Sticky hairs and bad smells are just the beginning of the methods of protection observed in the plant world. Watch below to see how plants can use bark, toxins, and help from other species to stay alive.