This hole opened within last couple days. I have a hole ( 1.5”, 1.75” diameter +/- ) appear several times per year, always within a few ( 10‘ ? ) feet . Sometimes with removed dirt piled on outside of hole and times like this with nothing. Lowest, wettest spot in yard. Stands water off and on. Dogs dont bother it, not attracted to a scent, nothing. As it opens off and on year round, have ruled out hibernating creature coming out in spring.