How do jellyfish move without a brain?

Jellyfish move without a brain by using a simple nerve net that coordinates their movements. They contract and relax their bell-shaped bodies to propel themselves through the water. This movement is supported by rhythmic pulses, allowing them to drift with ocean currents. While they lack a central nervous system, jellyfish rely on sensory cells to detect changes in light, temperature, and currents, guiding their movements and helping them survive.