Originally Posted by logefarm
We're building a new coop, and I'm considering using rare earth magnets for door closures. They range in strength- options include 10 lbs, 16 lbs, 40 lbs, 70 lbs and > 100 lbs of pull strength.
There will only be one door that is close to the ground, otherwise the coop doors and run door handles are elevated about 3-4 feet off the ground.
There will be a backup system with a piece of wood that turns to physically block the doors from opening.
So how strong do you think raccoons are??? I'm very curious to know. A google search revealed one raccoon that dragged a 40 lb bag of dog food across a yard...
All I can do is give you an anecdotal answer to that.
My friend and neighbor lost 14 chickens to a skunk. Realizing a skunk is not what you're asking about, the relative size between skunk and raccoon might give us an idea.
In the beginning, the damage caused by this skunk included breaking the welds on 2"x4" mesh field fencing to reach the pullets in a rearing cage. My friend's duck is kept in a chain link, free-standing old dog kennel/run. The skunk bent one of the clips used to hold the fencing to the metal frame, and was able to pull and bend the corner of the panel out about 4". Not enough to gain access, but it was quite a task. Neither she, nor I could bend it back with our bare hands.
Initially we thought we might be dealing with a black bear. Wolverines are capable, but don't usually come around civilization.
This skunk was finally caught, and weighed nearly 14 pounds! A freak of nature well fed on my neighbor's chickens.
My point being, an adult raccoon can out weigh even this skunk by 10 pounds. So I would judge strength accordingly. Dragging a 40 lb bag of dog food a few yard would seem easy enough. Add that to the fact that raccoons are highly intelligent, and have much more manual dexterity than any other 'pest' we might encounter. Also, being 2-3 feet long, standing on their hind legs they've been known to unlatch hook-and-eye fasteners to gain access to sheds.
You can only do what you can do. If you find a weakness in your security, you'll just have to deal with it as it arises. Can't anticipate every trick.