How do sea urchins protect themselves?

Sea urchins protect themselves using their spines, which act as a physical barrier against predators. Some species also have venomous spines or pincers called pedicellariae, which deter attackers. Sea urchins can hide in crevices or bury themselves in sand for additional protection. Their ability to cling to surfaces using tube feet helps them resist being dislodged by waves or predators.