Diagnostic characters
- Flat, squared-off face with two large central eyes
- Short, stout legs and a compact body
- Moves in short deliberate hops, pausing to orient the whole body toward objects of interest
- Iridescent chelicerae in many Phidippus males
- Often boldly patterned with white, orange, or metallic scales
Habitat and seasonality
Sunlit surfaces: exterior walls, fences, window frames, tree trunks, foliage, rock faces. Frequently enters homes and is often found on interior windowsills.
Diurnal and warmth-dependent; activity peaks on sunny days from spring through early autumn.
Medical significance
Low. Bites are rare, defensive, and produce brief localized pain. Phidippus bites can cause modest swelling that resolves without treatment.
Visual system
The anterior median eyes of a salticid form a telephoto optical system: a large corneal lens at the front of a long eye tube, with a small, movable four-layered retina at the back. Muscles swing the retina to scan the visual field without moving the head. Spatial acuity in Phidippus approaches that of a pigeon, which is extraordinary for an animal of this size.
The secondary eyes provide near-panoramic motion detection. A jumping spider detects movement laterally, pivots to bring the principal eyes onto the target, and only then decides whether to stalk.
Jumping mechanics
Spiders have no extensor muscles in the tibia-metatarsus joints of the legs. Extension is hydraulic: the spider raises hemolymph pressure in the prosoma and forces fluid into the legs. A jumping spider always attaches a silk dragline before leaping, which functions as both a safety line and a means of adjusting body orientation in mid-air.
Behavior in homes
Jumping spiders are among the few spiders that will orient toward and visually track a human observer, which is frequently reported as the spider watching the person. They are non-aggressive, non-web-building, and remove prey insects from windows and walls. There is no pest-management justification for control measures directed at this family.
Families most often confused with Salticidae
| Family | How to separate it |
|---|---|
| Oxyopidae | Lynx spiders have a hexagonal eye arrangement and long spiny legs |
| Thomisidae | Crab spiders hold their front legs laterally and do not jump |
| Corinnidae | Antmimics have small eyes of near-equal size and a glossy, ant-like body |
Profiled species in this family
| Species | Scientific name | Medical significance |
|---|---|---|
| Bold Jumping Spider | Phidippus audax | low |
References
- [1]World Spider Catalog, version 26 - Natural History Museum Bern. Accessed 2026-06-14.
- [2]Spiders of North America: An Identification Manual, 2nd ed. - American Arachnological Society. Accessed 2026-06-14.
- [3]Common Spiders of North America - University of California Press. Accessed 2026-06-14.