Hi Bone-sigh,
I can empathize with you, and appreciate how annoying it is when a wild animal is using your trees as a food source. I had mice munching on the roots of two of my trees this winter.
As peeved off as I was, and initially wanting to introduce the rodent responsible to the underside of my sledge hammer, I decided to look at it as my own fault. All the mouse was doing, was trying to survive, and so I moved the trees to a more secure location.
Perhaps erecting a large wire mesh enclosure of some sorts to protect all your trees, and/or even placing a good source of nuts and the like in another location in your garden, so that the squirrel is well fed, and has no need to eat your trees?
I normally don't agree with harming creatures in nature, apart from flies and wasps which will get splatted if they keep buzzing round me. I even let spiders live - mainly because I'm too much of a wuss to go anywhere near them lol
. Once, I told my dog "Get da bug", and she promptly ate this huge spider. 15 seconds later, the self same spider crawled out my dogs snout, which totally grossed everyone out lol.
In closing, I think pampering the little fellow may encourage it to leave your trees alone.
Regards,
Aaron
**Edit** You could train it to sit on your shoulder like the late Bob Ross - A truly gentle and inspiring man. RIP with your "Happy little trees"!!