What Is the Tiny Fuzzy Spider That Jumps? Identifying Jumping Spiders

Most spiders you encounter are trying to get away from you. Jumping spiders are the exception. Late summer is prime spider season, and one small, compact, often fuzzy spider has a habit of stopping on a wall, windowsill, fence, or leaf, swiveling to face whatever is watching it, and seeming to look right back at you — sometimes tracking your finger, sometimes cocking its body like a curious cat. If you have met a spider that appears to notice you and then hops away in a quick little leap, you have almost certainly met a jumping spider, one of the most likable spiders in the world.

How to Identify a Jumping Spider

Jumping spiders (family Salticidae) are usually easy to recognize once you know the combination of features:

• Size: small — most are between about an eighth and a half inch long, compact and often short-legged compared with a house or wolf spider
• Eyes: the giveaway. Two large, forward-facing eyes dominate the face like headlights, set among a total of eight, giving them a distinctly alert, "watching you" look
• Body and texture: a stout, rounded body that is frequently furry or velvety, often boldly patterned or iridescent — many have metallic green fangs or patches of white, red, or blue
• Behavior: active hunters by day that move in quick, deliberate stops and starts, and jump — sometimes several times their body length — to pounce on prey or cross a gap

One very common example in North American homes is the bold jumper, a black jumping spider with a white or orange triangular spot on its abdomen and shining green iridescent mouthparts. But jumping spiders are an enormous family with thousands of species worldwide, so colors and patterns vary widely — the constant is the compact fuzzy body, the big front eyes, and the hopping, inquisitive behavior.

How They Hunt (Without a Web)

Unlike orb weavers and cobweb spiders, jumping spiders do not build a web to catch food. They are visual, ambush-and-pounce hunters with some of the sharpest eyesight of any invertebrate, able to judge distance and stalk prey before leaping onto it. Before every jump they anchor a silk dragline to their starting point, so if they miss they simply climb back up — a built-in safety rope. They still use silk for shelter and egg sacs, but the acrobatics, not a trap, are how they make a living.

Are Jumping Spiders Dangerous?

For practical purposes, no. Jumping spiders are not considered dangerous to people. They are shy and far more likely to flee or leap away than to confront you, and they are not aggressive. Like nearly all spiders they can technically bite if trapped against skin or squeezed, but bites are uncommon and, for the vast majority of people, no worse than a minor sting with brief redness. They have no medically significant venom for humans.

In fact, jumping spiders are worth welcoming. They patrol windowsills, gardens, and walls eating flies, mosquitoes, and other small pests, and their curiosity and expressive "faces" have made them a favorite even among people who are wary of spiders. If one is indoors and you would rather it were out, the gentle approach is to coax it onto a piece of paper or into a cup and carry it outside.

Jumping Spider Look-Alikes

A few other small spiders get mistaken for jumping spiders, and the eyes and behavior usually settle it:

• Wolf spiders: also active ground hunters with good eyesight, but much larger and longer-legged, and they run rather than hop; their large eyes are arranged differently, without the two huge headlight eyes up front
• Ground and sac spiders: small wandering spiders that can look similar at a glance but lack the oversized forward eyes and the signature jumping movement
• Fishing and nursery-web spiders: bigger, longer-limbed spiders that may perch in the open but do not have the compact, fuzzy, big-eyed jumping-spider profile

Not sure whether the little spider watching you from the windowsill is a friendly jumping spider or something else? Snap a photo and let Spotter identify it, and you may find yourself rooting for the tiny hunter with the big eyes.