What are swimming rats called? - briefly
Rodents that habitually swim are generally called water rats; the most well‑known species are the muskrat (Ondatra zibethicus) and the water vole (Arvicola amphibius).
What are swimming rats called? - in detail
The term most commonly applied to rodents that habitually swim is “water rat.” In scientific literature the phrase designates several semi‑aquatic species, primarily within the family Muridae.
- Hydromys chrysogaster – known as the Australian water rat; inhabits freshwater streams and coastal lagoons in eastern Australia, possesses dense waterproof fur and webbed hind feet.
- Nectomys spp. – a group of South‑American water rats; occupy riverbanks and swamps, exhibit strong swimming ability and a diet rich in aquatic insects and small fish.
- Rattus norvegicus – the brown rat; while not a specialist, it is frequently observed swimming long distances and is sometimes referred to as a water rat in urban contexts.
These rodents share adaptations such as:
- Thick, water‑repellent pelage that reduces heat loss.
- Flattened tail used for steering.
- Hind limbs with partially webbed digits for propulsion.
The designation “water rat” thus serves as a collective name for multiple species that have evolved to exploit aquatic environments, rather than a single taxonomic entity.