Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.
Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.
Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.
Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.
Original illustration by PestControlBasics.com. Use anatomical labels above to confirm your identification.
🔍 Identification
Extremely long, thin legs (3-4x body length); very small body (7-8mm with legs extended to 70mm or more); tan/grey; builds loose, messy webs in corners of basements, crawl spaces, garages, and dark rooms. When disturbed, vibrates the web rapidly — making it appear blurry as a defense mechanism.
Note: 'Daddy long-legs' is also used for harvestmen (Opiliones order) — not true spiders and completely unrelated. The 'dangerous but can't bite' myth applies to cellar spiders and is 100% false — they can bite but the bite is harmless.
🧬 Biology & Behavior
Cellar spiders are generalist predators that feed on whatever insects and spiders they can catch in their webs. They actively hunt and kill black widows and other widows — placing them in the unique position of being beneficial pest control agents for dangerous spiders. They clean up other insects including mosquitoes that enter structures.
⚠️ Damage & Health Risk
Zero negative impact. Pure benefit. The only 'problem' is cosmetic — webs accumulate in corners. This is easily addressed by vacuuming webs periodically.
🔧 DIY Treatment
No treatment needed or warranted. If webs are cosmetically problematic, vacuum them. The spiders will rebuild webs, but regular vacuuming prevents large accumulations. Eliminating cellar spiders removes a beneficial layer of natural pest control.
👷 When to Call a Pro
Never warranted. Cellar spider presence in basements and crawl spaces is a net positive for pest management.