answer:@blueberry_kid They are indeed really cool. Have you seen pictures of the world’s largets species? Here;s a Lion’s Mane next to a scuba diver for comparison. How cool is that? Jellyfish don’t really have brains, but they do have a nervous system and are capable of processing sensory input and reacting to it. There nerve cells must have some features similar to the axons of neurons in a brain. They can sense the smell of food and move toward it. Some are more complex than others. Quite a few have primitive pigment-cup ocelli that let them detect where light is coming from. The “box jellyfish” is among the most venomous animals on the planet. Any major encounter between a human and a box jellyfish is nearly always fatal in minutes. Even a small sting from a broken-off bit of tentacle is excruciatingly painful and raises a large, keloid-type welt that lasts a lifetime. But dangerous as they are, they are also the most advanced of Jellies, with a complex nervous system and compact, umbrella form that lets them swim very fast. Box jellyfish have 32 true eyes complete with retinas, corneas and lenses. ranged in sets on their 4 sides around their circumference. Various eye sets are sensitive to radiation of different wavelengths. Obstacle-course tests show they can “see” and avoid obstacles. They can also “see” and pursue food or threatening animals. They aren’t able to see specific shapes, but can detect light verses dark areas and basic shape.