Spider behavior
Behavioral ecology of common spiders: defensive versus aggressive bite responses, indoor seasonality, web-building strategy, and dispersal.
- Behavior
Why spiders come indoors
Most spiders found inside North American homes are house-adapted species that live their entire lives indoors. They did not 'wander in' - they hatched there.
- Behavior
Are spiders aggressive?
No spider species in North America is aggressive toward humans in the behavioral sense. Bites are defensive and occur when the spider is pressed against skin (in clothing, bedding, or when handled).
- Behavior
Do spiders hunt in packs?
With rare exceptions among a few tropical species (Anelosimus eximius), spiders are solitary predators. They do not hunt cooperatively and do not have social colonies in temperate regions.
- Behavior
Ballooning: how spiderlings travel
Many spiderlings disperse by releasing silk strands into rising air and being carried aloft, sometimes for hundreds of kilometers. The behavior, called ballooning, exploits atmospheric electric fields as well as wind.
- Behavior
Courtship and mating behavior
Spider courtship is highly species-specific and often involves vibratory signaling, visual displays, or chemical cues. The diversity of courtship behavior is what allows so many sympatric species to avoid hybridization.
- Behavior
Prey capture strategies
Prey capture in spiders ranges from passive web ambush to active visual pursuit. The strategy a species uses is one of the strongest correlates of body plan, eye arrangement, and silk use.
- Behavior
Diurnal vs. nocturnal activity patterns
Most North American synanthropic spiders are nocturnal; jumping spiders and many crab spiders are strictly diurnal. Activity timing affects when sightings occur and how identification should proceed.
- Behavior
How spiders overwinter
Temperate spiders overwinter as eggs, juveniles, or adults depending on the species. Antifreeze compounds (glycerol, sorbitol) in hemolymph allow many species to survive subfreezing temperatures without freezing.