Große Fettspinne vs Common Dwarf Bonneted Bat

Steatoda grossa compared with Eumops bonariensis

Taxonomic Classification

Rank	Große Fettspinne	Common Dwarf Bonneted Bat
Kingdom same	Animalia (Tier)	Animalia (Tier)
Phylum	Arthropoda (Gliederfüßer)	Chordata (Chordatiere)
Class	Arachnida (Spinnentiere)	Mammalia (Säugetiere)
Order	Araneae (Webspinnen)	Chiroptera (Fledertiere)
Family	Theridiidae	Molossidae
Genus	Steatoda	Eumops
Species	Steatoda grossa	Eumops bonariensis

Evolutionary Relationship

Große Fettspinne and Common Dwarf Bonneted Bat share a common ancestor at the Kingdom level: Animalia. (Tier)

Conservation Status

Große Fettspinne

LC — Least Concern

Common Dwarf Bonneted Bat

LC — Least Concern

Physical Characteristics

Attribute	Große Fettspinne	Common Dwarf Bonneted Bat
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Große Fettspinne

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Africa (South Africa), Europe (29 countries), North America (Canada, United States), and South America (Ecuador).

Common Dwarf Bonneted Bat

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Venezuela.

Große Fettspinne

The false black widow (Steatoda grossa) is a cosmopolitan cobweb spider in the family Theridiidae, often mistaken for the true black widow due to its similarly dark, globose abdomen, though it lacks the red hourglass marking. Females reach 6–10 millimeters in body length and display a deep purplish-brown to nearly black coloration with faint pale markings on the dorsal abdomen. Originally native to western Europe, Steatoda grossa has spread globally through human commerce, establishing populations in Australia, New Zealand, North America, and other regions where it thrives in human structures including homes, sheds, and outbuildings. The spider constructs a persistent, tangled cobweb in sheltered corners and recesses, where it captures woodlice, ants, beetles, and other arthropods—notably targeting invertebrates that many other spiders avoid. The venom of S. grossa causes steatodism, a syndrome of localized pain, sweating, and systemic discomfort that is rarely serious but can cause significant distress. Interestingly, the antivenin produced for Latrodectus (true widow) spider bites has been shown to effectively treat Steatoda envenomations, underscoring the phylogenetic relatedness of these genera. Females produce several egg sacs during a season, each containing dozens of eggs wrapped in distinctive silken cocoons. The species is classified as Least Concern given its expanding global distribution facilitated by human activity.

Common Dwarf Bonneted Bat

<em>Eumops bonariensis</em>, the common dwarf bonneted bat, is a small molossid bat classified as Least Concern on the IUCN Red List, suggesting its populations are currently not under significant threat. The species has been recorded in Venezuela and is associated with diverse terrestrial and aquatic habitats, reflecting the broad ecological tolerance typical of many molossid bats. <em>Eumops bonariensis</em> belongs to the free-tailed bat family Molossidae and is characterized by its distinctive bonnet-shaped ears that extend over the forehead. Like other members of its genus, this species is adapted for fast, high-altitude flight and typically forages for flying insects in open airspace above forest canopies, wetlands, and urban areas. Molossid bats are known for their echolocation calls, which they use to detect and pursue prey during nocturnal foraging bouts. The species typically roosts in tree cavities, rock crevices, or man-made structures, forming small to moderate-sized colonies. Its insectivorous habits make it an important regulator of insect populations in tropical and subtropical ecosystems. Biological traits of this species remain poorly documented in the scientific literature.