Yikes, what town/city are you in?
We don't have them in our area, hawks are our problem with the chickens.
There was someone who posted some pictures and had a thread here a while ago about how a bear went in her coop and killed her chickens and tore the place apart.
I know it was at night but I don't think it was in the middle of the night.
Still though it was evening and the bear destroyed her coop and killed her chickens.
Maybe you can put up an electric fence to keep them away.
I didn't think bears would bother with bird food, who knew?
The more the cities build up and force the wildlife out of their homes the more we are going to see these incidents.
I am on a beekeeping forum and Connecticut is having a regular problem with bears from what the members are saying, someone posted a picture of a bear just walking down their road in the middle of the day without a care in the world.