The fox has a timetable; beat it
A fox visiting nightly is not wandering — it has a round, and your run is on it. It will come at roughly the same times, usually in the first hours of darkness and again before dawn, and it will test whatever it found almost-worked last night: the door that flexed, the corner where the mesh lifted, the one evening the hens were left out late. Most fox losses happen not through dramatic break-ins but on the single night the routine slipped. So the first defence is boring: hens locked inside a solid coop before dusk, every night, at a time that does not drift.
Wire that actually excludes
Chicken wire is named for what it does — it contains chickens. A fox can bite and tear through it. Runs that genuinely exclude foxes are covered, roof included, in welded mesh with a small gauge that a fox cannot force its head through, fixed to a solid frame rather than stapled loosely to posts. Check the corners and the door edges, where mesh is weakest and foxes push hardest, and repair the first sign of a curl or a gap: a fox remembers exactly where the weakness was and returns to work on it.
Latches, floors, and the digging apron
Foxes are surprisingly handy with simple fastenings — a sliding bolt or a lift latch that a hen-keeper works with one finger can be flipped by a determined fox, so fit latches that need two actions, or add a padlock for the visiting season. The coop itself needs a solid floor or a mesh skirt, because a fox that cannot get over will go under: bury mesh outward from the run's base, flat on the ground like an apron, so a digger hits wire the moment it starts tunnelling at the fence line.
Make the yard less rewarding
A fox that never succeeds usually moves on after a week or so of wasted visits — but it keeps coming while the yard pays. Spilled feed, food scraps, eggs left in an outside nest box, and bins it can raid all reward the round. Feed hens inside the run, collect eggs before evening, and clear the ground under feeders. A motion-sensor light over the coop unsettles some foxes and, just as usefully, tells you from the window that tonight's visit has started.
After a failed week, stay strict
The dangerous moment is relaxation: a fortnight of no losses feels like the problem has gone, when in fact the fox has simply been beaten nightly and is still checking. Keep the lock-up time, the latches, and the mesh inspections exactly as strict for as long as the visits continue, and tighten again the moment you add new birds, whose smell and noise renew a fox's interest. Word travels both ways on a street of chicken keepers, and KinsLe's Circle of Love is built for exactly that: nearby members connected through free accounts can pass on that a fox is working the area, so every coop on the lane is shut tight on the same nights.