Most of the insects use limb system for their movement but they follow different mode of locomotion according to their systems.

Movements in plants:
Plants also show movements like phototrophism, gravitrophism.
In response to light, plant grow towards the light. This phenomenon is called as phototropism. Whereas signalling molecules have their own roles in this process. Auxin is one them. It triggers shoot growth. Stems show positive phototropism and roots show negative phototropism.
The growth in response to gravity is called as geotrophism. Roots show positive geotrophism and stems show negative trophism. Here again auxin plays an important role in geotrophism.
Plant movement against contact stimuli is called as thigmotropism. Climbing plants such as vines are the examples for thigmotropism. When the plant touches some surface, the cell which contact the surface secrete the auxin to the untouched neighbour cell and induce them to grow long. This results bending around the object.