Perhaps a hundred or so golf ball size holes in lawn area, 70 ft. x 70ft. Soil is peat like over the top of sand and is seeded and growing grass. Have never seen what is causing the digging, showed up in spring as snow was going away in Michigan. There is a pond within 40-50 yards. This area sets alittle low, and get sun mostly in the morning. No soil is left on the top of grass, some burrowing was visible in grass in spring, all activity has ended in June, & July. Can put my finger down into the holes, many seem to run straight down. Please help ?? Holes are perfect diameter- they must come from below. thank you al
