<p>The Japanese giant flying squirrel is an arboreal mammal that mainly eats tree leaves. Some individuals first fold the leaf in half along the midvein using the mouth and next fold it vertically with the snout while holding the leaf with the forepaw. After partial eating of the corner of the folded leaf, they drop it on the ground. This leaf debris has an eaten hole in the center. We examined such leaf debris from six areas in Japan and found that the hole was usually located on the widest part of the leaf: near the tip of apically broad leaves, the middle of centrally broad leaves, and the base of basally broad leaves. This feeding behavior can be compared to the paper craft origami. We generated a paper leaf model with a clip that resembled the flying squirrel’s forepaw and found that the paper model is folded most compactly when clipped at the widest point along midvein. The compactly folded paper facilitates the next vertical folding. Thus, the flying squirrels learn the physical properties of leaves and make a fold at the widest part of the leaf, just like in origami.</p>