[Evans, Marv]

Coyotes around here seem to have a schedule of sorts. I believe it's because they have a loose circuit they follow, maybe depending on the season, where they find a better than average chance of finding food. I yours do, you might be able to figure out a time when they would be more likely to be around. Your dog most likely doesn't realize the danger and just goes after intruders onto the property. Coyotes are smart, and if you shot & killed one and the others realized that, they might not come around. Otherwise like said, they're waiting for a tasty dog treat.