Which is smaller: a shrew or a mouse? - briefly
A shrew typically measures 5–8 cm in body length, while a common mouse ranges from 7–10 cm, making the shrew the smaller mammal. Consequently, the shrew is smaller than the mouse.
Which is smaller: a shrew or a mouse? - in detail
Shrews and mice belong to distinct orders; shrews are insectivorous mammals of the order Eulipotyphla, while mice are rodents of the order Rodentia. Size comparison relies on body length (head‑to‑base of tail) and mass, both of which vary among species.
Typical adult shrew species, such as the common shrew (Sorex araneus), attain a head‑to‑body length of 55–82 mm and weigh 5–12 g. The smallest shrew, the Etruscan shrew (Suncus etruscus), measures 35–55 mm and weighs 1.2–2.7 g, representing the lower extreme for the group.
Typical adult house mouse (Mus musculus) exhibits a head‑to‑body length of 70–95 mm and a mass of 15–30 g. Smaller mouse species, like the Algerian mouse (Mus spretus), reach 60–80 mm in length and weigh 10–15 g, still exceeding the size of most shrews.
Consequently, the smallest members of the shrew family are lighter and shorter than even the smallest mouse species. The comparison can be summarized:
- Minimum shrew length: 35 mm; weight: ≈1.5 g.
- Minimum mouse length: 60 mm; weight: ≈10 g.
Therefore, the shrew group includes species that are consistently smaller in both dimensions than any mouse species. The distinction remains valid across the full range of adult sizes for each taxonomic group.