Squirrel replenishing its nest with dried leaves..

This afternoon I watched this Grey Squirrel going up and down this tree after collecting mouthfuls of dried leaves.  The nest hole is up about 18'.  Usually the squirrels replenish their nests with dried leaves when they are about to have more babies.  I've watched from my family room sofa, many generations of squirrel babies coming out of this nest, first just seeing a tiny head looking out of the hole, then a young one will come out while its mother is next to the hole.  Eventually 4 or 5 little ones appear at first just playing up and down the tree with each other until finally they venture forth out into the rest of our back yard.  A new generation again starts to try and get past our squirrel guard, to no avail, to reach the Sunflower seeds.  This winter's deep snow gave them a leaping off platform for them to reach the suet and feeder, but now there's no snow, it'll be fun watching them fathoming out different ways of beating the tubular guard.