I can speak from experience here. About 2 1/2 years ago, we went to bed with all 8 of our chickens doing just fine. We woke up to complete carnage. A bear had broken into our coop and killed 7 chickens, only eating 1. A year later, after adding an additional 11 hens to our flock, the same bear tried to come back for more. Luckily, we were able to scare him off before he got a hold of any of my girls. Once a bear finds out where a food source is, he's gonna keep coming back, and possibly also see if your house has any food in it too. It's best to get rid of the bear before any further destruction is caused. If you don't stand up to the bear and get rid of him, he'll keep coming for your chickens and might even go for your house. And I've had plenty of bear encounters, so I'm speaking from multiple experiences.