I was watching a special entitled "Predators of the Deep" on Underwater Universe.
http://animals.nationalgeographic.com/animals/invertebrates/box-jellyfish/We all know they're a deadly thing; venom enough to kill a human being in three minutes, delivered by reverse-fire needles in their tentacles, puncturing its prey with the force of a .45 bullet in a millisecond. They can grow to six feet, their tentacles drag for the majority of that length, and they're practically invisible in the right conditions.
But here's the part I didn't know.
Box jellyfish, unlike any other species of jellyfish, have 24 eyes - not photosensitive patches of skin, but eyes complete with lenses, retinas, corneas. They are also unique from almost all jellyfish species in that they can move on their own, rather than being slaves to ocean currents. For that matter, they seem to be able to determine where to drift in order to capture prey, not by instinct, but premeditation.
Now the "duh" moment; a box jellyfish doesn't have a brain.
Like I always say, I ain't no scientist. That being said, to operate a system of ambulation, premeditated attacks and 12 times the number of eyes a human has, with no higher functional system, is pretty amazing to me.
The more you know.