There are several schools of thought about that. The predator that kills one chicken will be back. So, you can turn your coop/run into Fort Knox. Or you can wait for the predator and then take him out. Problem solved for the short term, until a new predator moves in to take over the hole left in the ecosystem by the one you just took out. It becomes a repeating cycle. I'm of the philosophy: I'll do what I can to keep a strong perimiter, but ultimately, if it messes with my birds, I'm gonna take it out.
It takes longer to fill the hole in the ecosystem than it does for a persistent varmint to find its way in.
Short term, problem solved. Long term, just keep solving the same problem.
