It is easy for us humans to move backwards, forward and sideways, this is because of how our legs are attached to our bodies. The bending of the knee towards the front also makes walking forward easier. A crab’s legs, however, are attached to the side of its body. Its joints unlike our knees bend outwards, thus enabling the crab to only move sideways.
But do all Crab Walk Sideways?
There are a few crab species that can walk forward. These crabs have shells that are longer and wider. Crabs that walk sideways have shells that are wider than they are long.
Other animals move sideways too. The rattlesnake, for example, moves sideways as it makes its way in the desert.
Crabs are crustaceans and have five legs on each side of its hard shell. The front pair of legs is used for grasping food, for example and defence. The other four pairs are used for walking or swimming. Each leg has seven joints that are arranged so that the crab can walk sideways.
- Find 5 other animals which walk sideways.
- When you go to the beach, look around for crab nests. You will find several baby crabs moving in and out of their nests. Notice how they walk.
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