cobweb spiders vs Common Neacomys

Steatoda grossa compared with Neacomys spinosus

Taxonomic Classification

Rank	cobweb spiders	Common Neacomys
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Arachnida (Arachnids)	Mammalia (Mammals)
Order	Araneae (Araneae)	Rodentia (Rodents)
Family	Theridiidae	Cricetidae
Genus	Steatoda	Neacomys
Species	Steatoda grossa	Neacomys spinosus

Evolutionary Relationship

cobweb spiders and Common Neacomys share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

cobweb spiders

LC — Least Concern

Common Neacomys

LC — Least Concern

Physical Characteristics

Attribute	cobweb spiders	Common Neacomys
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

cobweb spiders

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 Neacomys

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Found in Colombia.

cobweb spiders

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 Neacomys

<em>Neacomys spinosus</em>, the common neacomys or spiny neacomys, is a small rodent in the family Cricetidae found in South America. This ground-dwelling mouse is characterized by its distinctively spiny fur, an adaptation that may provide protection against predators. <em>Neacomys spinosus</em> typically inhabits tropical lowland and montane forests, forest edges, and adjacent scrubby vegetation in northwestern South America, with its geographic range including Colombia and surrounding countries. The species forages on the forest floor and in low vegetation, and is believed to consume seeds, plant material, and invertebrates, although specific dietary data are limited. It is currently assessed as Least Concern by the IUCN, with populations considered stable across its range, though ongoing deforestation in the Amazonian and Andean foothills may present long-term threats. Biological traits such as lifespan, body size, and diet remain poorly documented for this species across its full range. <em>Neacomys spinosus</em> plays a role in seed dispersal and forms part of the prey base for small mammalian and avian predators in its tropical forest ecosystems.