Even you constructed your chicken coop out concrete block, or perhaps welded plate steel, a determined predator can find a way in. There are always weak points. Think doors for you or the chickens. Weak point. Think air vents. Weak point.
So, what is a protective chicken owner to do?
First off, build your coop as sturdily as you can or have the budget for. If you can slap a coop together with old wood pallets in an afternoon, a couple of raccoons can disassemble it in an evening.
Start with a deep rim.
Most digging predators will assume they can dig right at the base of a wall and go under said wall. Don’t make that mistake. When I started my coop, I laid down a perimeter of vertical 2 x 12 pressure treated lumber. This made a wall base that could not be pried up by your average critter. In areas where the 2 x 12s did not go all that deep, I added 12 inches of 1/2” hardware cloth going straight down and back-filled the trench. Most diggers don’t go deep. Foxes and Coyotes, in my experience, don’t like to dig all that much, but they will if it looks quick and easy. Don’t make it easy.
Cover all openings.
Coops need ventilation but cover all openings with 1/2” hardware cloth, firmly stapled or framed (with screws) such that a critter with claws can’t pull or push the mesh away. Even a hole the size of a 50-cent piece is big enough for a weasel to get in. I lost three “extra” roosters in the half-coop many years ago due to a hole in the coop wall where a drywall screw had pulled away enough flakeboard that the weasel could widen the hole and get in.
Barrel Bolts and Spring Hooks.
For doors and flaps that must open (without being pain in the butt), use barrel bolts. On taller doors, have one near the bottom too, so a raccoon can’t simply pry away at the bottom corner of a latched door and squeeze inside. For instances where a hook and eye are better, use one with a spring-activated cover. This is a little like two-factor authentication. One must pull away the cover first, then withdraw the hook.
Raccoons have perpetually busy fingers. They will fiddle with a lock and fiddle with it until they stumble across success. They’re not so much super-clever as persistent random fiddlers. Don’t have locks that are quick and easy to open. Easier for you. Easier for them.
Deny Them The Time
Even a well-built coop can eventually be breached if the predator has enough time to dig or pry or fiddle. The last layer of defense is a warning system that alerts you to the presence of something hanging around your coop.
My coop is vulnerable on its east and north faces as those can’t been from the house. The south and west sides have a further protection of garden fencing. It’s not as easy for a predator to access those walls. But, the north and east sides can be approached unseen from the woods.
Sensors Are Good, but Can’t Tell a Bunny From a Bobcat
To remedy the blind spots, I installed two 2×4 masts and mounted to them wireless driveway motion sensors. These worked great for alerting me that something was out there. For that first summer, I would rush out the back door with a my discouragement device (with mounted flashlight) to see what it was. Too many times, it was a harmless skunk or a possum passing through. I was getting tired of Red Alerts that were nothing.
Cameras: A Game Changer
The solution was adding wifi cameras with pan and tilt. That has been a great addition. Now, when a sensor is triggered, I can look on the appropriate camera to see what set it off. Most of the time, it’s something harmless: a skunk, a possum, or a bunny. Even when it has been something more serious, like raccoons or bobcats, I can see if they’re just ambling through or looking for trouble. No need to rush out with the tool if they only passing through.
One time, the #2 sensor went off at a time it normally doesn’t. (Squirrels or chipmunks sometimes set it off during the day). The camera revealed a family of four raccoons sitting in the flat tarp roof of the half-run. They were clearly not passing through. Four sets of fiddling fingers could create an exploit. They needed to be chased away or dealt with in harsher terms. In their case, two were chased away. Two experienced harshness.
Even the bobcats tend to be lazy opportunists. Many times, they would prowl through but not linger much. One, however, had designs. I watched him via the camera sitting and studying the north face of the coop. He was not moving along, but hatching something. So, for him, I stealthily moved around, my hand over the mounted light until the last second. I surprised him. He got a couple of going-away packets, though none connected.
The Techno-Layer
Any coop can be breached if the predator has enough undisturbed time to find a way in. My two sensors alert me to prowlers. The cameras let me decide if it’s an urgent matter or no big deal.
My coop and run aren’t Fort Knox, but the walls haven’t been breached in ten years.
If you can’t afford to build Coop Knox, consider adding a technology layer to let you know if it’s determined predator, or just a bunny.