Eight smart limbs plus a big brain add up to a weird and wondrous kind of intelligence

Someone is watching you, intently, but you can’t see them. Then you notice, drawn somehow by their eyes. You’re amid a sponge garden, the seafloor scattered with shrublike clumps of bright orange sponge. Tangled in one of these sponges and the gray-green seaweed around it is an animal about the size of a cat. Its body seems to be everywhere and nowhere. The only parts you can keep a fix on are a small head and the two eyes. As you make your way around the sponge, so, too, do those eyes, keeping their distance, keeping part of the sponge between the two of you. The creature’s color perfectly matches the seaweed, except that some of its skin is folded into tiny, towerlike peaks with tips that match the orange of the sponge. Eventually it raises its head high, then rockets away under jet propulsion. Read more …