I've been thinking about this.   It started happening within a week of us cutting down a 'group' of 4 pines (set in a line, not far from coop/run) that needed to come down before they blew down on the house. [Note, there is no other way in for them BUT digging, as the rest has mesh wire over it, or for the coop proper, solid wood with mesh for ventilation ports]
There are still 2 VERY large pines in the run, but they need a crane, and estimates are $4500, so they will have to wait.  The Flying Squirrels were on the pine in the run.  Maybe it is just coincidence that the digging started when then were forcibly relocated by us cutting down the pines??  I'll have to relocate my 1 game cam to verify.
Monday Mugs:
View attachment 3024553View attachment 3024554View attachment 3024555
Bonus mugshot:  Butler...where are you...let me in!
View attachment 3024556