Touch pads: The Red Squirrels has a remarkable sense of touch. They have 3 highly sensitive touch pads on each of their hands. By shifting a nut between their front paws, they can actually feel, if a nut is empty, half full, completely full, rotten or if it has a worm inside it, without even opening it. So if you find the same 4 nuts left alone in your nut feeder time and time again, there's something wrong with them, just throw them away. By shifting the nut around in their hands, they can determine, if it's worth the time and effort, grinding through the thick nut shell. If the nut inside is too small, rotten or has a worm, it's simply not worth the time, energy or effort. As every ounce of time, energy and effort, has to be spend wisely when living in the wild.
Nails: The red squirrels nails are incredibly strong! They can literally hang themselves and hold themselves up, with just one nail. Imagine if you could lift your own body weight, with just one finger, let alone a finger nail.
Thumbs: It believed that they used to have fully functional thumbs, but as squirrels have soft and flexible skeletons, it's very hard to find them as fossils. So the theory goes: As you can see on the pictures, their thumbs is almost gone. It almost looks like it has been amputated. And it kind of has, by mother nature and evolution. Unlike their rear legs, which we talked about the other day, the arms can not rotate 180 degrees. Which means that if they crawled upside down, side to side with full sized thumbs, they would literally break off. So to be able to crawl super fast, up and down, side to side on a tree trunk, it simply got worn down over time, from generation to generation and eventually, leaving only the first joint of the thumbs. Although limited in movements, it mainly functions to hold food as they eat. It still has a tiny nail attached to it, but it doesn't grow like the rest of the fingers, but acts as a shield from damaging their highly sensitive finger skin. Other animals, related to squirrels with fully functional thumbs are Flying squirrels and sugar gliders.