The problem a skirt solves
Most coop break-ins do not come over the top or through the door. They come underneath. Foxes, raccoons, stray dogs, mink and rats all share one simple method: walk up to the fence or coop wall, and dig where the barrier meets the ground. A run can have a roof, strong latches and solid walls and still lose its flock in a night to an animal that went under in twenty minutes. The hardware cloth skirt exists to defeat exactly that move, cheaply and permanently, by changing what a digging predator finds when its paws start working at the base of your coop.
What the skirt actually is
Hardware cloth is not cloth at all: it is a stiff, galvanised welded-wire mesh, far stronger than the thin hexagonal chicken wire sold beside it. A skirt, sometimes called an apron, is a band of that mesh, usually in a small grid such as half-inch, attached to the bottom of the coop or run wall and extending outward horizontally along the ground, commonly a foot to a foot and a half wide. It is pinned down with landscape staples, weighed with stones or slabs, or covered with a shallow layer of turf and soil so it lies flat and disappears. The top edge is screwed or stapled firmly to the coop's base rail so there is no gap where wall, mesh and ground meet.
Why outward works better than downward
The clever part of the skirt is geometry. A digging predator almost always starts its hole tight against the fence line, because that is where the barrier is. Digging there, it immediately meets mesh under the soil and cannot get through it; crucially, it does not think to back up a foot and a half and start again beyond the apron, because the mesh it can smell and scratch at is right at the wall. Burying mesh vertically can work too, but it means digging a deep trench all the way round, and buried wire rusts unseen and fails silently. A surface skirt achieves the same protection with a fraction of the labour, and you can inspect it at a glance whenever you walk the run.
Fitting one properly
Fit the skirt to every side of the coop and run, corners included, because a predator only needs the one side you skipped. Overlap joints by a few inches and tie them with wire so no gap opens up, cut carefully around door thresholds and then add a mesh strip under the door itself, and take the same apron around any connected structure, such as a feed store or a fixed dust-bath frame. Wear gloves and mind the cut edges, which are sharp enough to deserve respect. Once it is down, grass grows through it and holds it in place, and the whole system asks for nothing more than an occasional check that soil, slabs or turf still cover it fully.
One layer in a secure coop
A skirt stops diggers; it does not stop climbers, reach-through paws or animals that test the door, so it belongs inside a complete setup: hardware cloth rather than chicken wire on the run walls, two-step latches a raccoon's hands cannot work, and a roof or covered top where climbing predators are a risk. When the setup is finished, write it down for the household: KinsLe's Family Sharing lets everyone who feeds, locks up or covers holiday care for your flock see how the coop is secured and what to check, so the skirt and latches get the same attention whoever does the evening round.