Using gravity to outsmart a predator.


11 Years
Oct 25, 2008
Eugene, OR
I have worked on a number of automatic opening and closing coop door designs. I just completed my latest version when I had an idea that has nothing to do with a door as security from a predator. In fact, theoretically, you could have no coop door.

Imagine coop that is raised up a few feet. And a door only accessible by ramp. Now, what if you were to construct the ramp with seesaw type mechanics so that a lightweight hen could travel across the board and up to the door of the coop. But a heavier raccoon, possum, fox, etc would weigh down the board before getting to the door opening. Sure, if two hens were following one another in line, this could potentially trigger the board but then the board would snap back and each would get unlimited chances to enter the coop individually.
One weakness would be a young predator that could weigh as much as an adult hen/rooster, but I don't know if that is even realistic. This idea probably wouldn't work in places where weasels live and predate on hens.

Essentially this is a weight triggered trap door. Instead of a seesaw, you could have part of an entrance board that has a weight sensitive trap door.
Of course there would have to be no other way an animal could gain access to the coop door other than the entrance plank for this to work.

Has anyone ever thought of something like this? And what could be some real weaknesses in a predator aversion tactic like this?

A great idea that would probably work if the coop was not climbable. I have a coop with a long ramp that sits 3-feet off the ground with a 6-foot ramp for access. My problem (with coons anyways) is that they would climb right up the legs. Maybe use steel pipe for legs instead of wood? Not sure how far coons can jump but my guess is the coop would need to be at least 4' off the ground to prevent a coon from gaining access by simply standling on their hind legs. Interesting idea.
I have been tossing around an idea of some sort of tunnel entrance that is accessed by a short flight to a roost that enters the tunnel. Haven't worked it all out in my head yet, but..... somewhere there is a way to use the fact that they can fly (most preds can't) to restrict access to unwanted guests. How about running several concentric strands of hot wire around the popdoor (4' off the floor) and fixing a landing roost just out from the center of it. Just ideas so far...
I think you are underestimating how good of jumpers and climbers that many predators are. I've seen a cat go from the ground to the top of a seven foot fence in one leap, not even using the fence to help the jump. It was one huge, fluid motion and BAM cat was magically on top of the fence. Heavier and less nimble predators like possums and raccoons may have issues, but rats, weasels, and mink would have no problem. Rats are excellent jumpers, (my former housemate's pet rat could jump up an incredibly distance to get to a treat), as are foxes.
I agree a motivated predator can do amazing things but a slick surface would seem to help discourage them. how about a horizontal ladder entrance with slit PVC around the uprights that spin or move if grabbed. The chickens can hop from rung to rung and perch on them but it may be too slick for a coon and too far between rungs for other critters? Just an idea.... have fun with the challenge
My coop I am finishing actually is 4' off the ground, and yes, I do not underestimate the cunning and physical abilities of a predator like the raccoon.
My coop is built on 4x4s, but I imagine one could use those dog collar cones or some similar design to keep coons from climbing up it. I know they are excellent climbers. So, it would seem ideal to have no jump off points to other parts of coop. For instance, mine stands right next to a fence and a tree, which both can provide access to the secure roof and non-door sides. So, if a raccoon can climb across, up or down the 4' painted wood surfaces of the coop, even an unbeatable seesaw mechanism could potentially be bypassed.

The area I live in could be a wonderful testing grounds for something like this however, because many raccoons live very close by.
I have coops elevated 7 feet above ground. Chickens have to fly 7 feet up to a rope for first landing point. Rope is too unstable for predators capable of making jump (i.e. bobcat, fox, coyote) but OK for chicken. The fact it is up and elevated within roost makes it difficult for great horned owls and red-tailed hawk to swoop under and up into. All these predators could defeat if they had time to practice but chickens will make ruckuss and dog will cut practice time short.

Where possible, make use of chickens flying ability, especially the vertical with manuevering using small wings. I do not know how but chickens, at least mine, seem better than typical hawk when perching on wiggly perch. And avian predators not so smart. Make it so they can see chickens but not through access point to roost / coop. The avian predators seem inclined to take direct route which is not always possible owing to material roost / coop is made. Crows can think their way around such but for most folks, crows not an issue.
Thinking of removing the 3' wooden legs on my coop and adding metal pipe 4' legs. I already have a electric fencer in use - simple matter to attach jumper wires to each steel leg....
I think this idea is really intriguing! In fact, it already exists too, but for discouraging squirrels. I have seen feeds that are weight sensitive, and when anything heavier than a bird stands on the lip, it depresses and closes the feeder. That could easily be translated to a landing in front of a coop door.

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