Net-casting Spider

Instead of building a fixed web and waiting, it makes a small hand-held net and actively hunts with it. At dusk the spider spins a rectangular patch of extremely stretchy, wool-like silk, roughly a centimetre or two across at rest, and holds it gathered between the claws of its four front legs. It then hangs upside down from a few anchor lines, positioned just above an insect runway or a bare patch of ground, and waits, sometimes marking the target zone with tiny dabs of white silk or droppings as an aiming point. When an insect walks or flies into range, the spider thrusts its legs outward, stretching the net to many times its resting area, and sweeps it down over walking prey or backward through the air to trap a flying insect, then wraps and bites the catch.

The net-casting spider hunts at night and relies on vision to detect and aim at prey, so it has evolved the largest simple eyes of any spider — the rear-middle pair, which bulge forward and give the animal its "ogre-faced" look. Unlike cats and many nocturnal animals, it has no tapetum (the mirror that produces eyeshine). Instead, each large eye rebuilds a huge, delicate, light-gathering photoreceptor membrane every evening and breaks it down again at dawn, because the membrane is too fragile and light-sensitive to survive daylight. This gives the spider extraordinary low-light sensitivity, estimated to exceed that of cats and owls, letting it see prey on a moonless night.

No. It is a small, shy, slow spider with weak venom suited to subduing insects, and it has no interest in biting humans. Bites are very rarely reported and cause only minor, short-lived local pain and swelling, less than a bee sting. In Australia, where net-casting spiders are common in suburban gardens and often hunt near porch lights, they are considered harmless and even beneficial for the number of insects they remove. The main way people encounter one is by noticing a strange stick-like spider hanging in the foliage at night with a small pale net held in its front legs.

Effectively, yes. Research on the Australian net-casting spider Deinopis has shown that it can detect airborne sounds, particularly low-frequency vibrations, from up to about two metres away using fine sensory hairs and slit organs on its legs, without any eardrum. When it senses the wingbeat or flight noise of an insect passing behind it, it performs an accurate backward strike with the net, capturing prey it never saw. So the spider uses its giant eyes for prey in front of it and on the ground, and a kind of vibration-based "hearing" through its legs for prey approaching from behind and above.