Use bacon drippings, meat drippings, {just store them in old tin cans and freeze until ready to use!} To this add peanut butter, egg shells (washed), figs or dates or raisins, seeds and apple or other fruit pieces all chopped finely. Also add flour, bread crumbs or oatmeal to make it thick. Put it on a greased flat cookie sheet, freeze and cut with a pizza cutter. They love it.