Predator-Proofing: The Six Attacks and the Five Defences

Attack 1: The reach-through

Raccoons cannot unlatch most standard slide bolts — but they do not need to. Their hands fit through standard chicken wire (2-inch hexagonal mesh) and through welded wire with openings larger than 1 inch. They reach in, grab a hen by the neck, and pull. The result looks like a mystery: the birds are dead inside a locked coop with no obvious entry point.

The defence: hardware cloth with half-inch openings on every wall, window, and vent. Hardware cloth is not cheap — $60-90 for a 10-foot by 3-foot roll — but it is the only material that stops a reach-through. No exceptions for the lower 18 inches of any exterior surface.

Attack 2: The dig-under

Foxes and dogs (and occasionally coyotes and badgers) dig under run walls that terminate at ground level. A motivated red fox can clear 12 inches of topsoil in 30 minutes. I have found a cleanly dug fox tunnel under a 6-inch-deep run skirt precisely 9 days after the run was completed.

The defence: an apron of hardware cloth 12 inches wide laid horizontally outward from the base of the run, staked flat to the ground. The animal begins digging at the base of the wire, hits the apron 3-4 inches out, cannot understand what is blocking it, and gives up. Burying the apron 2 inches deepens this by another 30 seconds of confusion; most foxes quit before that. Do not attempt a vertical underground skirt deeper than 12 inches — it requires a trencher and does not work better than the horizontal apron approach.

Attack 3: The pull-open

Raccoons can operate spring latches, twist-pull latches, and sliding bolt latches that require one motion to open. The internet is full of videos. I have personally watched a raccoon open a two-step carabiner clip in 4 minutes on a trail camera.

The defence: two-step latches that require two simultaneous or sequential motions — push-and-slide, or a carabiner through a slide bolt ring. The raccoon has hands but not the bilateral dexterity to operate two motions simultaneously. Padlocks work but are overkill for most keepers. A locking carabiner (the kind that requires twisting the gate before depressing) has not been defeated in any trial I am aware of at standard raccoon testing.

Attack 4: The aerial strike

Cooper's hawks, red-tailed hawks, great horned owls, and eagles are the aerial predators most backyard keepers will face, in descending order of frequency in suburban settings. A Cooper's hawk will follow your hens into the run if the top is uncovered. It will also hit a bird within two feet of you.

The defence: a covered run. Hardware cloth or bird netting across the top eliminates aerial attack entirely. For large runs (above 500 square feet), bird netting at $0.10-0.20 per square foot is more practical than hardware cloth. The netting does not stop a great horned owl if it lands and waits — but great horned owls hunt at dusk and dawn, and most suburban keepers lock birds up at dusk.

For free-range flocks: roosters call alarm. One rooster per 20 hens is the historical ratio for hawk detection.

Attack 5: The squeeze-through

Weasels, minks, and young rats squeeze through any opening larger than 1 inch. A weasel can pass its entire body through a 1-inch gap; its skull is the limiting factor, and a weasel skull is smaller than a golf ball. They kill more birds than they eat — one mink loose in a coop overnight has killed 40 birds in a single documented case.

The defence: half-inch hardware cloth, no exceptions. Quarter-inch is overkill and substantially more expensive. Pay attention to pipe penetrations (water lines, electrical conduit) — these are common entry points that builders overlook. A 1-inch gap around a water pipe is a weasel door.

Attack 6: The gnaw-through

Rats. The domestic rat can chew through 1/4-inch welded wire and through wood framing with a half-inch square cross section. They are motivated by feed, not by killing birds — but once inside, they stress birds enough to drop laying rates by 40 percent, and they bite sleeping birds on the feet and comb.

The defence: metal feed containers, not plastic. No feed left in the coop overnight. Welded wire (not hardware cloth — welded wire is thicker gauge) on the lower 12 inches of the run. Snap traps set outside the run on rat runs (identifiable by grease marks along walls and fence lines).