What does Battista do to make Cosimo come home and what is the result of her action?

Battista sneaks out in the night to the tree on which Cosimo perches every morning and covers it everywhere she can with glue. The morning finds the tree covered with birds and feathers of birds, squirrel tails, leaves, and the corner of Cosimo's coat, but no Cosimo. The tree remains in its pitiful state for quite a long time, and eventually dies.