Broad-faced Sac Spider

Scientific Name: Trachelas tranquillus

Order & Family: Araneae, Corinnidae

Size: Males 3-8 mm, Females 5-10 mm (body length)

Broad-faced Sac Spider

Natural Habitat

Found in various habitats, including under rocks, leaf litter, rotting logs, and sometimes indoors in homes, especially in cooler weather.

Diet & Feeding

Predatory, feeding on other small arthropods and insects.

Behavior Patterns

Nocturnal hunters, they do not build webs for catching prey but rather actively stalk and pounce on their victims. During the day, they hide in silk sacs (hence the 'sac spider' name) under bark, leaves, or in crevices.

Risks & Benefits

While generally not aggressive, they can bite if trapped or threatened. The bite is usually not medically significant, often compared to a bee sting, and localized pain, redness, and swelling are common. They can be beneficial as they prey on other household pests.

Identified on: 9/30/2025