Where is the organ of hearing in cancer?

The crayfish has 2 pairs of antennae, which are located on the head. One pair is long, the other pair is short. It is the short antennae that are the organ of hearing and balance. A grain of sand is placed in the recess of the short antennae, which, when moved, irritates the receptors of sensitive hairs. This is how cancer determines its spatial position. When an animal sheds its chitinous cover during molting, this grain of sand also disappears, and the animal cannot orient itself in space.