There is almost no nourishment in the bogs that Venus fly trap's grow in. So they have adapted to get the nourishment they need by capturing insects and then dissolving them.
Notice that the traps do not change when stroked by a finger on the outside, just on the inside, as if a fly was trapped...
Playing time: 3 minutes. No sound, so you concentrate on the movement. (For hints on using videos click here.)
