I have had many a tree be attacked by Rodents, primarily Squirrels which attack the roots and also the bark on trunks and limbs. I lost both of my Beech trees when Squirrels attacked and ate half of the roots on my two Beech trees. I had these trees for years and had just put them both in Bonsai pots the previous year. Do what you must to protect your trees and learn how to save them if you can.
REPAIRING RODENT DAMAGED BONSAI by Bill Valavanis New 11-01-2020