In a scorpion tail, there is only the ball, meaning the round edge of the joint. The lack of a socket allows the tail segments to bend up and down, twist left and right, ...

Unlike lizards, however, these scorpions have a peculiar anatomy in which their anus resides near their stinger at the end of the tail. Thus, when a scorpion breaks off its tail, it comes at a ...

So, when a scorpion performs autotomy, it leaves the final bits of its digestive tract writhing on the ground. And since the tail never grows back, that scorpion can never defecate again.