How Do Spiders Hunt Without a Web?

A jumping spider freezes on a sunlit stem, eyes locked on a fly thirty body lengths away. It stalks a few millimeters, freezes again, adjusts its angle by degrees, then leaps ten to forty times its own body length with a silk dragline already anchored behind it as a safety line. There is no web anywhere in this hunt. No sticky trap, no waiting. Just calculation and a very precise jump.

Most spiders will eat almost any animal small enough to subdue, but the strategies different families use to get there rival the range of hunting styles seen across every vertebrate predator on Earth combined. Ambush, pursuit, chemical lure, disguise, fishing, cooperative attack, and even stealing prey directly from another spider's web all show up somewhere in the spider world, each one the product of long selection pressure in a particular habitat.

The short answer

Roughly half of all known spider species hunt without ever building a capture web, relying instead on eyesight, vibration sensing, ambush, or direct pursuit. Jumping spiders stalk and leap using some of the sharpest vision of any small animal. Fishing spiders hunt from the surface of water. Spitting spiders immobilize prey with a venomous glue fired from a distance. Net-casting spiders throw a small handheld web instead of leaving one fixed in place. Each strategy solves the same problem, catching food, with completely different tools.

Jumping spiders hunt like small cats with a safety rope

Jumping spiders form the family Salticidae, the largest spider family on Earth with more than 6,000 described species. Most stay under 20 millimeters long, with compact bodies and enormous forward-facing principal eyes built like long, narrow telephoto tubes. Inside each one sits a four-layered retina that detects color, including ultraviolet light invisible to humans, and scans back and forth internally while the outer lens itself stays completely fixed.

From a distance, a jumping spider identifies what kind of prey it is looking at, judges what defenses it might have, and chooses an attack path before it moves a single leg. Lab studies have found something rarer still: jumping spiders show goal-directed flexibility unusual among invertebrates. In test arenas, they will take longer routes that briefly move them away from visible prey, purely because that detour leads to a better strike position once the target passes out of direct view. Pulling that off requires holding a target's location in mind across a stretch of travel where the target itself is no longer visible, a kind of working memory rarely documented outside vertebrates.

Hunting on top of the water

Fishing spiders, in the genus Dolomedes, stand directly on the surface film of ponds and slow streams, supported by dense hydrophobic hairs on their legs that keep them from breaking through the water tension. Ripples from insects, tadpoles, and small fish moving nearby travel across that surface film to vibration-sensitive hairs on the spider's legs, and the spider strikes down from above or plunges beneath the surface to seize aquatic prey directly.

Some individuals subdue fish up to five times their own body weight, inject venom to stop the struggle, then drag the catch back to shore to feed at leisure. It is one of the few hunting strategies in the spider world that treats the water's surface as solid ground.

Immobilization at a distance and a net that expands tenfold

Spitting spiders, genus Scytodes, move the whole immobilization step outside their own body. They spit a venomous, sticky liquid in a zigzag pattern from the chelicerae toward prey up to two centimeters away, and the entire event lasts about one seven-hundredth of a second, far too fast for the target to escape. The spit is both adhesive and toxic at once, pinning the prey in place and beginning digestion before the spider even walks over to finish the job.

Net-casting spiders take a third approach entirely. They hold a small rectangular web stretched between their front legs, hanging head-down from a branch or stem, and throw it directly over prey that passes underneath. At the moment of the strike, they expand that net up to ten times its resting area to maximize the catch. Their massive front eyes, proportionally the largest of any spider family, feed the low-light vision this kind of night ambush depends on.

Every strategy ends at the same meal

Across all of these hunting styles, one limit stays constant: spiders cannot chew solid food, so every kill ends in external digestion. Venom immobilizes the prey, enzymes liquefy its internal tissue, and the spider drinks the resulting protein-rich liquid, leaving behind a dry, hollow husk. Every hunting style on this list, from a calculated jump to a fired glue shot to a fish hauled out of a pond, ends at the same quiet feast: a protein shake pulled from an exoskeleton, efficient enough to power eyes, silk glands, and leaps on a body that can fit on a coin.

What the numbers show

• Jumping spiders form the family Salticidae, with more than 6,000 described species.
• Fishing spiders can subdue fish up to five times their own body weight.
• A spitting spider's strike lasts about one seven-hundredth of a second.
• Net-casting spiders expand their handheld web up to ten times its resting size at the moment of the strike.

Terms worth knowing

Salticidae

The jumping spider family, the largest spider family, known for sharp eyesight and calculated leaps.

Principal eyes

A jumping spider's large forward-facing eyes, built like internal telephoto lenses for judging prey and distance.

Kleptoparasitism

Stealing prey directly from another spider's web rather than catching food independently.

External digestion

The process by which a spider liquefies prey tissue with enzymes outside its own body, then drinks the result.

Related field notes

All Spiders field notes

Web-building spiders get most of the attention, but this half of the family tree hunts with eyesight, vibration, and raw athleticism instead. Spiders Decoded covers every strategy in full, alongside the silk and venom systems that make all of them possible.