Broad-faced Sac Spider / Trachelas tranquillus
Scientific Name: Trachelas tranquillus
Order & Family: Araneae (spiders) / Trachelidae (sac spiders)
Size: Males: 5-8 mm (body length); Females: 7-10 mm (body length).
Natural Habitat
Commonly found in leaf litter, under rocks, logs, and debris outdoors. They frequently enter homes and buildings, especially in cooler weather.
Diet & Feeding
Primarily other small insects and arthropods.
Behavior Patterns
Fast moving, nocturnal hunters. They do not build webs for prey capture but may use silk for retreat building or egg sacs.
Risks & Benefits
Generally considered beneficial as predators of other insects. Bites are rare but can occur if provoked or accidentally trapped against skin. The venom is not medically significant for humans and typically results in localized pain, redness, and swelling, similar to a bee sting. No long-term effects are expected.
Identified on: 8/24/2025