Fixing pesk hole in coop

[Bananaplinko]

I found the hole dug under the chain link fence surrounding the coop. Luckily no birds are missing. Any ideas on what made it and how to fill it so something can’t get back in?

 

[1muttsfan]

Just about any critter could dig a hole like that. You could bury wire in a trench around your perimeter, or put down an apron of chicken wire, you can easily find out how in the coop section. In addition, I see you use chain link fence, that is really insecure especially down low as a raccoon could easily reach through grab a chicken and kill it. You might consider covering at least the lowest 3 ft of your run with hardware cloth.