The coyotes coming to the bay is likely a territorial defense response. Coyotes don't like any other canine in their territory.
Staging a bay might be a good way to whack some coyotes.
Dave
x2...especially at this time of the year when they have pups...a friend of mine has a 3/4 mtn cur 1/4 pit that loves a good coyote...that dog can make the fur and poop fly from one...