Dog Chewing Waspers

What does it mean to look like a dog chewing waspers? Or like a possum eating persimmons? And what does it mean when someone says, “He was grinning like a mule eating briars”? These idioms, which have been recorded in Kentucky and Virginia, refer to people chewing with their mouths open in a less-than-civilized fashion. In all of these examples, the one who’s masticating is showing lots of teeth — rather like a beagle trying to eat a sliding glass door. This is part of a complete episode.