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Plants don't have nerves or brains, but they can still detect mechanical stimulation.
Touching, wind, rain, and physical contact can activate cellular signals and alter how some plants grow.
A famous example is the sensitive plant, Mimosa pudica, whose leaves rapidly fold after being touched.
Other responses are much slower and may involve changes in growth rather than visible movement.
Being rooted in one place doesn't mean a plant is unaware of physical changes happening around it.
© University of Western Australia