Harmless, and probably the most likeable spider you will meet. It has no medically significant venom and would rather watch you than bite you. The one shown here is the bold jumper, the species most people encounter in North America, but the whole family behaves the same way.
Size4–18 mm depending on species; the bold jumper is 8–15 mm
MarkingsTwo enormous forward-facing eyes, with a row of smaller ones around the head · Turns its whole body to look at you — nothing else does this so obviously
WhereSunny vertical surfaces — fences, walls, window frames, plant stems and garden furniture. Indoors they gravitate to windowsills where the light is.
SeasonActive in daylight through spring, summer and early autumn
How to tell it apart
Two enormous forward-facing eyes, with a row of smaller ones around the head
Turns its whole body to look at you — nothing else does this so obviously
Short, stocky, and fuzzy rather than long-legged
No capture web; it stalks and pounces, trailing a silk dragline
Bold jumpers are black with a white or orange triangle on the abdomen and iridescent green fangs
Where you’ll find it
Everywhere. There are over 300 species in North America and more than 6,000 worldwide, making Salticidae the largest spider family on earth. Whatever part of the US you are in, you have jumping spiders.
Sunny vertical surfaces — fences, walls, window frames, plant stems and garden furniture. Indoors they gravitate to windowsills where the light is.
Active in daylight through spring, summer and early autumn.
How it behaves
This is the spider that appears to be looking at you, because it is. Jumping spiders have the sharpest vision of any spider and among the best of any animal their size — good enough to recognise shapes and track movement across a room. They hunt by stalking, then jumping, using a sudden change in blood pressure rather than muscle to launch. They always anchor a silk line first, so a missed jump is a swing rather than a fall. Many species court with elaborate dances, waving their front legs.
What a bite looks like
Bites are rare enough to be a curiosity. Where one happens it leaves a small red mark comparable to a nettle sting, and it fades within a day.
A brief pinprick, if anything at all.
We identify, we don't diagnose. A jumping spider bite needs nothing more than washing, but see a doctor if any bite becomes swollen or infected.
A skin mark cannot confirm which animal caused it. Read the bug bite and sting guide for the limits and the symptoms that should end an online search.
You’ve found one indoors
Leave it alone and enjoy it. Jumping spiders eat the insects you would rather not have and cannot damage anything. If you want it outside, they will usually walk onto a piece of paper without any fuss — they are curious rather than fearful.
Common questions
Are jumping spiders dangerous to humans?
No. They have venom for subduing insects, but it is not medically significant to people, and they very rarely bite even when handled.
Why is it looking at me?
Because it can see you. Jumping spiders have by far the best vision of any spider — their two large forward eyes resolve real detail — and they turn to track anything that moves. It is assessing whether you are prey, a threat, or neither.
How far can a jumping spider jump?
Many times its own body length. They do it hydraulically, by forcing body fluid into the legs, rather than with muscle, and they always trail a silk safety line first.
Can you keep a jumping spider as a pet?
People do. They are among the few spiders that seem to notice their keeper, which is most of the appeal. Wild ones are best left where they are — they are doing useful work in your garden.
Rebecca Ray · CC-BY