Though many of us have seen pictures of a huge eagle's nest high in the branches of a tree or in the crag of a cliff, few of us have gotten a glimpse inside. When a mother eagle builds her nest she starts with thorns, broken branches, sharp rocks, and a number of other items that seem entirely unsuitable for the project. But then she lines the nest with a thick padding of wool, feathers, and fur from animals she has killed, making it soft and comfortable for the eggs. By the time the growing birds reach flying age, the comfort of the nest and the luxury of free meals make them quite reluctant to leave. That's when the mother eagle begins 'stirring up the nest.? With her strong talons she begins pulling up the thick carpet of fur and feathers, bringing the sharp rocks and branches to the surface. As more of the bedding gets plucked up, the nest becomes more uncomfortable for the young eagles. Eventually, this and other urgings prompt the growing eagles to leave their once-comfortable abode and move on to more mature behavior.