Cobweb weaver vs Polynesian rat

Steatoda nobilis compared with Rattus exulans

Key Differences

• Cobweb weaver is Not Evaluated while Polynesian rat is Least Concern.

Taxonomic Classification

Rank	Cobweb weaver	Polynesian rat
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Arachnida (Arachnids)	Mammalia (Mammals)
Order	Araneae (Araneae)	Rodentia (Rodents)
Family	Theridiidae	Muridae (Mice & Rats)
Genus	Steatoda	Rattus
Species	Steatoda nobilis	Rattus exulans

Evolutionary Relationship

Cobweb weaver and Polynesian rat share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cobweb weaver

NE — Not Evaluated

Polynesian rat

LC — Least Concern

Physical Characteristics

Attribute	Cobweb weaver	Polynesian rat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cobweb weaver

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Europe (7 countries), North America (United States), and South America (Ecuador).

Polynesian rat

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical coniferous forests, among 4 distinct biome types spanning the Australasia and Indomalayan realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (6 countries), Europe (United Kingdom), North America (United States), Oceania and the Pacific (11 countries), and South America (Chile).

Cobweb weaver

The noble false widow (Steatoda nobilis) is a theridiid spider that has attracted considerable media attention in the British Isles and along the Atlantic coast of Europe due to its painful but rarely dangerous bite and its rapid range expansion facilitated by human activity. Originally native to the Canary Islands and Madeira, the species arrived in southern England during the 19th century, likely via banana shipments, and has since spread northward through Britain and westward into Ireland, while also establishing populations along the Iberian Peninsula and Atlantic France. Females are robust, with a dark brown carapace and a distinctive cream-colored pattern on the bulbous abdomen that varies between individuals; females reach 8.5–14 millimeters in body length, making this one of the larger European theridiids. The species constructs persistent, tangled cobwebs in sheltered locations outside buildings—under window ledges, in door frames, and in garden walls—as well as within homes in cooler seasons. It is a generalist predator, capturing insects and other invertebrates, and has been reported to occasionally subdue prey considerably larger than itself, including small lizards. Steatoda nobilis venom produces steatodism, which can cause localized pain, swelling, and in rare cases systemic symptoms. Its conservation status has not been formally assessed, but its expanding range demonstrates considerable resilience.

Shared Countries

Both species can be found in 2 countries:

🇬🇧 United Kingdom 🇺🇸 United States