Jumping spiders don’t have super legs. It’d be easy to think that these tiny creatures have insanely muscular legs given their ability to leap up to 50 times their own body length. This is not the case, however. Instead, jumping spiders rely on segmented legs and blood flow to make their crazy jumps.
When they’re ready to jump, the spiders cause an extreme change in hemolymph pressure (the spider equivalent of blood pressure) by contracting the muscles in the upper region of their bodies. This forces the blood to their legs, and this causes the legs to extend rapidly. This quick and sudden extension of their legs is what propels them in the direction they’re aiming.
Jumping spiders don’t use webs to hunt. Well, why would they? Their jumping abilities are how they catch their prey. They find a target, extend their legs and launch after their meal, which is typically small insects. A little bit of venom and it’s dinnertime. One species, the Bagheera kiplingi, eats plant matter, while another species eat nectar.
Some jumping spiders, however, go for more dangerous game by turning the tables on would-be predators. Regal jumping spiders have been known to attack and eat small frogs and lizards. And if you’re worried about jumping spiders hunting you, don’t worry. They can’t produce enough venom to hurt us.
Jumping spiders may not have ears, but they hear very well. But how do they hear? Sensory hairs along their bodies take in vibration of sound waves, and that action sends signals to the spiders’ brains. Researchers discovered this by accident in 2016. They were studying the spiders’ eyes, but their method for doing so demonstrated that vibrations sent neurons firing, even vibrations that originated some 10 feet away.
