File this under things we knew: Cat tongues are scratchy. File this under things we can’t believe we’ve just learned: Tiny hooks spring up on a cat’s tongue when it licks and grooms. And those hooks have built-in scoops to carry kitty saliva into thick fur for a deep clean.
Scientists used high-tech scans and some other tricks to learn—finally—how those sandpapery tongues really work. A team of mechanical engineers reported the findings in November. The team says its new knowledge could lead to inventions for pets and people both!
Georgia Tech lead researcher Alexis Noel is seeking a patent for a 3-D printed, tongue-inspired brush. She believes it could be useful for cleaning carpets or applying medicine to hairy skin.
Noel’s interest in cat tongue technology began when her own cat, Murphy, got his tongue stuck in a fuzzy blanket. Scientists thought cat tongues were studded with tiny cone-shaped bumps—but that didn’t support Noel’s Murphy observation. In this case, curiosity didn’t kill the cat. But it did prompt Noel to understand hers better.
She was already working in a lab known for animal-inspired engineering, so she put her questions to the test there. A CT scan showed that cat’s tongues are not covered in solid cones. They have claw-shaped hooks. These hooks lie flat and rear-facing, out of the way until, with just a twitch of a tiny muscle, the little spines spring straight up. But that’s not all. Those spines contain hollow scoops, Noel discovered. She turned to zoos and taxidermists for more cat-variety tongues. She found that many large cats—like lions and bobcats—all share that trait.
Noel discovered that those spines wick up the liquid. A housecat has nearly 300 spines—called papillae—on its tongue. The tongue is wet with saliva. As a cat licks, those papillae wick up the saliva and transfer it to its fur.
Next Noel measured cat fur. Not only is every hair numbered by our God, but even the distance between the hair and the skin is measured. When cat fur is compressed, the distance from the surface to the skin matches the length of the spines on a cat’s tongue. What a magnificent discovery of God’s precision in His design! (The Persian cat is an exception. Its super-long fur was bred intentionally by human-directed selection. The spines on a Persian’s tongue are not longer to match. That’s why that breed must be brushed daily.)
Plant and animal designs inspire many human inventions. Copying functions from nature into modern technology is called biomimicry. How do you think the cat-tongue discovery might be used in the future?