Eastern gray squirrel

At the nature reserve where I volunteer, there are several large bird boxes very high in trees, hoisted up there as an Eagle scout project to provide great horned owls with homes. I have never seen signs of owls in these boxes but did see the other day that a squirrel family had moved into one. They are obviously not worried about being "sitting ducks" as prey for any owl that might happen by. I usually see them on the ground or scurrying up and down trees. I do think they looked very cute observing the world below from their high perch!