Cat Tongues and Papillae

Alexis Noel and David Hu have been researching cat tongues as reported in the Proceedings of the National Academy of Sciences (December 2018). Using 3-D scanning with micro-computed tomography, they have discovered some interesting things.

The backward facing barbs (papillae) on cat tongues are not cones as had been previously thought. They are actually hollow structures similar to scoops for dipping ice cream. They have a U-shaped cavity that holds fluids extremely well. This shape enables cats to use the force of surface tension to pull up water as they lap it. It also allows them to wick saliva deep into their fur. When cats lick themselves, saliva is distributed all the way down to the roots of the hairs. Cats don’t have sweat glands except on their paws, so the distribution of saliva removes heat from their skin.

The papillae also allow cats to lick up oils and other contaminants on their fur. This not only keeps the cat clean, but it avoids odors. Applying this discovery may open the door to a whole new line of materials for use in home and industry. Dr. Noel gives one word of warning. Don’t let your cat lick a microfiber blanket, because the cat’s tongue will stick to the blanket!

Cat tongues are not like sandpaper but rather like Velcro. Velcro was discovered by scientists watching other examples in the natural world. Humans have copied the design of materials found in living organisms to create many of the substances we take for granted. We see God’s creative genius everywhere we look. “We can know there is a God through the things He has made” (Romans 1:19-20).
— John N. Clayton © 2019