Will the fox remember forever that he got chickens in my yard? I love letting my chickens free range, but obviously not if they're getting eaten! So now I'm worried that I won't ever be able to let them free range again...
I would say yes...if he's looking for food, he'll keep coming back until there are no chickens left. You may want to set up a trap or depending on the laws...try and catch him in the act and shoot him. But again, look into the laws before you do that. I hate killing something like that, but sometimes you have no choice if you want to protect your livestock.