Question

Why do crabs walk sideways?

Answer 1

The bending of the knee towards the front also makes walking forward easier. A crabs 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. There are a few crab species that can walk forward.

Answer 2

Hey user, here is your answer...
___________________________________
Why do crabs walk sideways?

▶Because they have their feet(claws) is attached to the side of their body which acts like a joint and their knee bends outwards which enables them to walk sideways.
___________________________________
Hope it helps.
Thanks for the question.