We have ordered an electric fence and motion sensor; putting up motion light tomorrow. We are reinforcing the coop and limiting areas bears can grab onto the walls. Seriously considered building a cinder block coop. I like the nails idea so we may add some. Unwelcome mats if we need to. Haven’t had issues with predators in a year and a half other than a hawk (through the fence), so we had to rethink some things.
We are almost positive that the bear that attacked our chickens was killed on the third night by a hunter. He returned the second evening at dusk to sniff around but hasn’t been seen since. It’s rare for multiple bears of that size to be in a small area where we live, but still possible. We are hoping to have enough time to prepare before another bear finds us. We were prepared to kill him the third night since we had heard that he would continue to return to eat any new chickens, our koi fish, get into sheds, house, etc. but we were called by a neighbor who knew of the bear hunt kill nearby.
Thanks for the advice on the feed and good luck with your bear situation!