Good Morning Gentle Readers,
A friend of mine had some problems with the local vermin decimating her fruit crop and leaving the seeds lying about on the ground. Sounds like rats or ground squirrels to moi. Birds just peck the heck (rhymes!) outta the fruit.
Here is a simple way to keep assorted vermin out of your trees.
Go to Home Despot, Lowes, or any building supply store or yard and pick up a roll of galvanized steel flashing. This particular flashing is twelve inches wide. You'll need wider if you plan to keep possums out of an avocado tree.
Gahhh! Used to make me crazy when I lived in Fullerton. Those nasty things would get up in the avocado tree and go from fruit to fruit, making sure to ruin all of the avocados, never eating more than a few bites from each.
Fashion the flashing into an inverted cone and fasten with a screw in a couple of places to hold it fast. The vermin can't get a grip on the slick steel flashing and they slide off.
Warning: Rats are smart and they are persistent. If you look carefully down to the left of my cone, you can see where the rats have gnawed at the steel flashing, which is pretty thick stuff. The other damage is from The Boy and his BB gun.
In addition, rats can jump, so make sure they don't have easy access to tree branches from the roof or fence or your work will be in vain.
Course, a pile of cats works a lot better at keeping rats, mice, gophers, squirrels, possum, and various other obnoxious pests out of your fruit trees. But some people are allergic and others don't like felines.
Oh, and use bird netting when the fruit begins to get ripe.