A squirrel (family Sciuridae) that has a membrane (patagium) between its wrists and ankles. When it extends its limbs to the sides the patagium acts like a wing, allowing the squirrel to glide between trees, using its long tail for stability and moving its limbs to steer. Gliding allows the animal to conserve energy while moving at high speed and foraging over a large area. Flying squirrels feed on fruit, fungi, and birds’ eggs, and forage by both night and day. There are 44 species found worldwide.