Witness the sensitive plant's rapid movement when touched, which may be a defense mechanism

Native to South and Central America, the sensitive plant is a widespread weed in tropical regions and is sometimes grown as a novelty for its rapid plant movement.
When touched, the sensitive plant swiftly closes its compound leaves and droops.
It slowly returns to its normal state after some minutes.
Scientists are unsure exactly why the plant evolved this curious mechanism, but it is possible that it serves to frighten away hungry herbivores.