Why jumping spiders look different from other BC spiders
Jumping spiders are immediately recognisable if you know what you're looking at. They're compact and robust (not the long-legged profile of house spiders), typically 5–12 mm body length, and covered in dense hair or scales that can produce iridescent colour patterns. But the most distinctive feature is the eyes. Jumping spiders have eight eyes arranged in three rows — the front pair are enormous relative to body size, forward-facing, and give the spider true binocular vision. These large anterior median eyes are what produce the 'face' that many people find either charming or unsettling.
The jumping spider visual system is among the most sophisticated in the invertebrate world. The large front eyes have a narrow field of view but exceptional resolution — some Salticidae species can resolve objects at distances 20–30 times their body length. They move their retinas internally to track moving prey rather than turning their heads. The secondary eyes provide wide-field motion detection. This combination makes jumping spiders extraordinarily effective hunters in three-dimensional environments like foliage, window frames, and exterior walls.
Common BC jumping spider species
| Species | Size | Appearance | Where found |
|---|---|---|---|
| Phidippus johnsoni (red-backed jumping spider) | 8-12 mm | Black with red abdomen (male), orange-spotted (female) | Gardens, fences, exterior walls |
| Phidippus borealis | 8-12 mm | Hairy, grey-black with white markings | Interior walls, window frames |
| Menemerus bivittatus (grey wall jumper) | 7-10 mm | Grey with white stripes | Exterior walls, sun-exposed surfaces |
| Habronattus spp. | 4-7 mm | Variable coloured with leg ornaments | Ground level, garden, grass |
| Marpissa species | 5-8 mm | Brown, elongate profile | Bark, fence posts, garden structures |
Behaviour: the watching, the jumping, the approach
Jumping spiders are diurnal — they hunt in daylight and rest at night. This is part of why they're more often noticed than other BC spiders: they're active when people are awake. They're also unusually curious. If you approach a jumping spider slowly, it will turn to face you, track your movement, and often move slightly toward you — not aggressively, but with the attention of an animal that relies on its vision. People find this either endearing or alarming depending on their arachnid comfort level.
The jumping itself is precise and controlled. Jumping spiders anchor a silk dragline before jumping — if they miss, the line stops them from falling. They can jump 10–20 times their body length when hunting or escaping, which is what produces the startling appearance-on-the-wall or face-at-eye-level encounters that alarm people. They're not jumping at you. They're navigating their environment using three-dimensional movement that happens to occasionally involve your vicinity.
Why jumping spiders are in your home
Jumping spiders enter homes through gaps around windows, door frames, and in weatherproofing — the same entry points that other spiders use. They're not seeking the dark, damp conditions that house spiders prefer. Jumping spiders like light: sunny windows, south-facing walls, glass surfaces where they can hunt the small flies and gnats attracted to light. A jumping spider on your window frame is there because the glass is warm and well-lit and there are insects to catch.
Indoors, jumping spiders are typically temporary visitors rather than permanent residents. They don't build the large, persistent webs of house spiders. They build small silk retreats (tube-like structures in tight gaps) for overnight shelter and egg laying, but they range actively during the day and don't concentrate in basements or dark corners the way Tegenaria and Eratigena do. A jumping spider in your living room has usually come in through a gap and will navigate back out when conditions change.
Safety: the complete picture
Jumping spider bites in BC are essentially unknown. The spiders are small, their fangs are targeted at prey insects, and they don't exhibit defensive biting behaviour toward humans. In controlled experiments where researchers have handled hundreds of jumping spiders, bites occur only when the spider is physically compressed — squeezed between fingers or similar. Even in those cases, the bite produces only minor local sensation, equivalent to a pin prick. There is no venom component in BC jumping spiders that produces systemic reactions. They are the least medically relevant spider you will commonly encounter in Metro Vancouver.