Let's say you are playing a course in the north central USA. Your ball ends up in a freshly excavated hole located in the center of the fairway. It is a bit smaller than your fist. It is pretty clearly not a divot hole. You do not know what sort of animal made the hole. It could have been a fox squirrel (tree dweller) digging for a nut or it might be a ground squirrel's attempt to start a new home.
One gets relief from a hole made by a burrowing animal. There is no relief from a non-burrowing animal (like a fox squirrel) unless the committee marked the area as GUR. Do you take a penalty stroke to get relief because you can't say with certainty that this was made by a burrowing animal while in a similar situation, a local zoologist gets free relief because she recognizes the species that made the hole (ground squirrel)?
I would be inclined to call it a hole made by a burrowing animal unless I witnessed the critter doing it AND knew the animal did not create holes for burrows or protection.
What do you think? I could not find a Decision on point but maybe I missed it.