Image of the Day: Hair Brush

Cats’ tongues are covered in tiny spines called papillae, which help wick moisture from the mouth and onto the fur.

Nov 20, 2018
Catherine Offord

ABOVE: The tip of this domestic cat’s tongue is covered in rigid, hollow papillae (right), while the part of the tongue nearer the throat is covered in softer, conical papillae (left).

Domestic cats spend up to a quarter of their waking time licking their fur to remove fleas and debris and to reduce body temperature. To groom, felines rely on tiny, keratinous spines called papillae on the surface of their tongues.

Researchers Alexis Noel and David Hu of Georgia Tech have recorded high-resolution images and video of the action of postmortem tongue tissue from six feline species, ranging from domestic cats to snow leopards. They found that the papillae’s tips are particularly well-shaped to wick saliva from the mouth and onto the fur to aid cleaning.

The pair has also created an artificial brush inspired by the structure of the papillae, which Noel and Hu suggest in their paper could be used to remove allergens from cat fur by hand or to apply medications to cat skin.

A black cat cleans its fur, revealing the papillae on its tongue.

A.C. Noel, D.L. Hu, “Cats use hollow papillae to wick saliva into fur,” PNAS, doi:10.1073/pnas.1809544115, 2018.

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