I doubt a coyote would eat its dead brethren unless it was really desperate. Road killed deer on the other hand work quite well for a bait pile. One winter in ND, I got permits from the sheriff's dept to pick up dead deer on the roadside. The pile had 5 or 6 by March and brought in skunks, coyotes, racoons, and a bald eagle. Big stinking mess though when things warmed up.