Cheek pouch

In some rodents, such as hamsters, the cheek pouches are remarkably developed; they form two bags ranging from the mouth to the front of the shoulders.

[4] Étienne Geoffroy Saint-Hilaire described that some bats of the genus Nycteris have an amazing form of cheek pouches, as they have a narrow opening, through which the bat can introduce air, closing the nasal canal through a special mechanism and pushing air under the skin, so they expire in the tissue, which unites the very loose skin to the underlying muscles.

[4] Cheek pouches have several roles; they allow the rapid collection of food, but also serve as temporary storage and transport.

[7][18][19] Below is the introduction of the legume (pod) of peanut in the cheek pouch of a chipmunk: One of the classic behavioral characteristics of hamsters (subfamily Cricetinae) is food hoarding.

[22] The cheek pouch is a specific morphological feature that is evident in particular subgroups of rodents (e.g. Heteromyidae and Geomyidae, or gopher), yet a common misconception is that certain families, such as Muridae (including the common black and brown rats), contain this structure when in fact their cheeks are merely elastic due to a high degree of musculature and innervation in the region.

Volumetric analyses within this study attributed the differences in net cheek volume between male and female rats to the average size of the respective sexes.

The primary aforementioned muscle, the masseter, is supplied by two large neural branches known as the temporalis and zygomatic nerves.

[25] The buccal divisions of this nerve supply much of the masseter muscle, which ultimately facilitates the voluntary retention of food within the cheek pouch.