I have been experimenting with creating videos of plants lately. This one was shot using a webcam and it worked reasonably well.
This is an example of a nastic response to a stimulus. Specifically it is thigmonasty, a non-directional response to touch or vibration. The leaf of a venus flytrap is divided into two lobes, each of which bears three trichomes (hair-like structures). The closing of the “trap” is triggered by touching one of the little trigger hairs twice or by hitting two of them in succession. Somehow this causes a change in turgor pressure in the cells of the leaf and a rapid change in shape, allowing the trap to close rapidly.