Cobweb spider vs Greater Sac-winged Bat

Enoplognatha thoracica compared with Saccopteryx bilineata

Key Differences

• Cobweb spider is Vulnerable while Greater Sac-winged Bat is Least Concern.

Taxonomic Classification

Rank	Cobweb spider	Greater Sac-winged Bat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Arachnida (Arachnids)	Mammalia (Mammals)
Order	Araneae (Araneae)	Chiroptera (Bats)
Family	Theridiidae	Emballonuridae
Genus	Enoplognatha	Saccopteryx
Species	Enoplognatha thoracica	Saccopteryx bilineata

Evolutionary Relationship

Cobweb spider and Greater Sac-winged Bat share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cobweb spider

VU — Vulnerable

Greater Sac-winged Bat

LC — Least Concern

Physical Characteristics

Attribute	Cobweb spider	Greater Sac-winged Bat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cobweb spider

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Found across Europe (4 countries) and North America (Canada, United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Greater Sac-winged Bat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Colombia, Ecuador, and Venezuela.

Cobweb spider

Enoplognatha thoracica is a slender cobweb spider in the family Theridiidae, a widespread group of three-dimensional web-building spiders found across the temperate regions of Europe and North America. This small spider, typically measuring 3–5 millimeters in body length, constructs irregular, tangled cobwebs in low vegetation, hedgerows, meadow margins, and scrubby habitats where it captures small flying and crawling arthropods. The body is pale yellowish-brown to creamy white with darker markings on the abdomen, and the legs are long and slender relative to body size, adapted for navigating the three-dimensional structure of its web. Like other theridiids, Enoplognatha thoracica uses a gum-foot trap technique in which sticky vertical threads attached to the substrate at their lower ends snap insects upward when disturbed, immobilizing prey effectively. The species occupies a range spanning much of Europe eastward into temperate Asia and has established populations in parts of North America, likely through accidental human-mediated dispersal. Females produce egg sacs that are guarded within the web until hatching. The species is associated with disturbed and edge habitats and tolerates moderate agricultural landscapes. It is classified as Vulnerable by some assessments, reflecting localized population pressures from habitat loss and intensification of land use in parts of its range, though other evaluations consider it more broadly secure.