Portia, an eight-millimetre jumping spider, stalks a spider-eating Scytodes. Her exceptional eyes build a 3D mental map as she tests the web with deceptive signals that fail to lure the predator. Recognizing a frontal assault would be fatal, Portia plots a circuitous approach from above, out of sight.

A male of her species arrives, studying both Portia and the Scytodes. Something changes in Portia’s calculations: the male becomes an “ally,” expanding her strategic options. They nonverbally coordinate. Portia maneuvers to a high vantage while the male edges onto the web, masking his movements with wind-shaken strands.

The male signals convincing prey-like vibrations, drawing the Scytodes into motion. Seizing the moment, Portia drops from above and injects venom, swiftly immobilizing the spider-eater. After feeding, tension oscillates between treating the male as prey and not-prey, yet cooperation persists, letting them tackle risks they would avoid alone.

Instincts then reassert: they mate, and the partnership ends. Portia lays a large clutch. Both carry a nanovirus, and their offspring will be larger, brighter, and more successful. Through rapid, selective evolution across generations, Portia’s descendants are set to flourish and ultimately inherit the world.