"Spiders invert this relationship -- they are 2D specialists that slice a 3D space with a trap, capturing 3D specialists without expending energy to navigate th

"Spiders invert this relationship -- they are 2D specialists that slice a 3D space with a trap, capturing 3D specialists without expending energy to navigate their prey's space." I think that's a great way to put it, although "spiders" really should say "orb weaving spiders". Jumping spiders don't build a web, they are active hunters in the 3D space with the ability to plan several steps ahead. Although they can't fly, they definitely hunt in 3D and don't really conserve energy. Huntsman spiders are also active hunters, but mostly in 2D and waiting from an ambush position. They don't build a web. Neither do crab spiders, but I'd agree that these two families of spiders are trap-based and largely passive, even if the trap is not a web. Labyrinth spiders (funnel web spiders) are a fun anomaly due to the complexity of their trap, which is 3D, but arguably it's a still a passive way to hunt. My favorite would be the net-casting spider, which builds a tiny web that it holds, and then casts on its prey. The timing and coordination of that is mind blowing: https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s https://www.youtube.com/watch?v=QyRPrax9MJU&t=19s