How many nails does a rat have? - briefly
A rat has a total of 18 nails, with five on each forelimb and four on each hindlimb.
How many nails does a rat have? - in detail
Rats possess a total of ten keratinized claws. Each forelimb bears five nails: four functional toes and a reduced dewclaw that carries a small nail. Each hindlimb also carries five nails, one on each of its five toes. The nails are curved, sharp, and composed of hard keratin, enabling the animal to climb, dig, and manipulate objects.
- Forepaws: four primary digits + one dewclaw → 5 nails
- Hind paws: five digits → 5 nails
The distribution is consistent across common laboratory and wild species (e.g., Rattus norvegicus and Rattus rattus). Developmentally, the nail plates form from ectodermal tissue during embryogenesis and grow continuously throughout the rat’s life. Their size and curvature vary slightly between fore and hind limbs, reflecting functional differences in locomotion and foraging behavior.