Displacement of body.
Mostly animals show locomotion except porifera, urochordata, corals, obelia thier larva may show locomotion.
Its importance is -
1. Search of shelter, food & water.
2. Escape from predators.
3. Escape from unfavourable environment.
4. Collect material for nest building.
5. Find a suitable mate for reproduction.
6. Locate suitable area for breeding.
7. Disperse to new locations.