animal high spirits

And Trok threw back his head and laughed with animal high spirits.

Sara herself was "a marvelous figure of a Negro woman with broad nose, full lips, and noble brow" who "fascinated men-folk and women-folk alike with her animal high spirits, flashing smile, and raucous laugh."

Lydia's elopement with Wickham is the most distressing incident in the book and, since it is based on no more than animal high spirits on her part and sexual attraction , is unlikely to be lastingly happy.