Do jellyfish have brains?

Jellyfish do not have brains, and most barely have nervous systems. They have primitive nerve cells that help them orient themselves in the water and sense light and touch. Jellyfish can be tiny or grow to several feet in diameter.

Jellyfish have bodies like bells or umbrellas. They get their name because of the jelly-like material found between the two layers of cells that make up their bodies.

Jellyfish use stinging cells on their tentacles to both capture food and protect themselves from predators. These stinging cells penetrate flesh like minuscule darts and remain active even after the animal is dead.