Some years ago I had the chance to tag alongwith a state traper for a day. His favorite bait was urine and a dead snake and a couple of frogs in an old quart size pickle jar. Every time he got a coyote, he would empty the bladder into this jar. He would set it out in the sun for a day or two and when he opened it, I made sure I was up wind from him. He took seven yotes that day. one of which I killed with a 20ga. and #6 shot at twenty yards.