Above the irrigation ditch on our farm was a rocky area of unimproved land. In these rocks lived rodents we called rock chucks. Larger than rabbits, they were pests because they would come down into our field of wheat for meals on a regular basis. One day Dad had had enough and took me and his 22 caliber rifle up to the ditch bank. There were willows growing along the bank and Dad selected a nice green barked willow about half an inch in diameter to make a whistle. After a few minutes he had made a whistle for me and another one for himself, then we crouched down and he made a chirping sound with the whistle to imitate the sound of a rock chuck. When they popped their heads up out of the rocks, to see where the noisy rock chuck was, he would shoot it, thus diminishing the losses in his wheat field.