Tiny thumbnails may be key for rodents’ global takeover
Having nails on their thumbs may give rodents the dexterity to crack open nuts
Thumbnails may give rodents the dexterity needed to crack open seeds and nuts. Here a southern giant slender-tailed cloud rat (Phloeomys cumingi), a thumbnail-bearing rodent native to the Philippines, holds food with its hands.
Forest Botial-Jarvis