Bug Identifier
Spider Egg Sac
Community identification

Spider Egg Sac

Araneae (Order level)

Order & Family
Order: Araneae; Family: Varies (commonly associated with House Spiders like Parasteatoda tepidariorum or Cellar Spiders)
Size
Typically 6–10 mm diameter for the sac itself (size varies significantly by species).
See this bug in the Encyclopedia

Natural Habitat

Found worldwide in varied environments; commonly located indoors in corners of ceilings, attics, basements, undisturbed closets, and garages.

Diet & Feeding

The sac itself is inanimate protection; the spiderlings inside will eventually emerge and consume small insects (flies, mosquitoes, ants) or sometimes cannibalize siblings.

Behavior Patterns

Female spiders spin a silk protective covering around a clutch of eggs. Some species carry the sac (like Wolf Spiders), while others (like the one likely pictured) suspend it in a web. After a few weeks, hundreds of tiny spiderlings hatch and disperse.

Risks & Benefits

Generally harmless. Benefits: Spiders are crucial pest controllers that eat nuisance insects. Risks: While most house spiders are non-venomous to humans, seeing many sacs may indicate a large spider population. The spiderlings are rarely dangerous.