We have several foxes that come prowling at night - thankfully not in the day as our orchard is a high traffick area (I live in a school).
The coop is secure and we've never had a problem as long as the girls are all locked up before dark.
Unfortunately someone opened the coop last year and we lost the entire flock in one go. I ran out with the dog (3am) but those left were so injured that they died over the next few days :-(
I sympathise with wanting to get rid of them, but from what I understand they are super territorial and even if you kill the whole family, this son surrounding boundaries just extend their territory to cover the gap