Just going to put this out there: they started calling me “Wicked Mike” years ago for a reason. My collection is up to over two thousand varieties of chiles, before you get into the other stuff. I’m not an expert on anything at all, but I’m pretty well-versed in all things Capsicum.
Peppers will work here. Had a problem with squirrels digging up my pepper plants to bury acorns. Thought, “well, I’ll teach those furry little b**stards a lesson they won’t soon forget.” Had a lot of dehydrated superhot s on my hands (as always). Ground them down into dust and sprinkled it around my plants, thinking I’d light ‘em up good.
I never got the chance.
Here’s the thing: the first peppers weren’t hot. It’s a survival adaptation to discourage small mammals. Makes sense, when you thing about it. Birds fly. They tend to disperse seeds over wide distances. By comparison, small herbivorous mammals don’t. It’s in the plant’s best interest that small, herbivorous mammals don’t eat the fruit.
Comparable to the evolutionary adaptation in Passifloras. The unripe fruit contain procyanogens, which become cyanide in a mammal’s body. When the seeds are viable, the procyanogens disappear, and the fruit magically becomes aromatic, delicious, nutritious, and more often than not changes color and/or falls on the ground.
Not magic, but science.
If you want to get pretty much any mammal to leave your plants alone, I’d recommend scattering the dried, powdered form of the hottest pepper you can lay hands on. Be aware that you’ll want to wear gloves and a mask and long sleeves. This is not something you want to get on your skin, take my word. You’ll have to do it fairly often, depending on rainfall/irrigation, but with the correct application, I’m pretty sure this would be effective even with bears.