Australian and New Zealand Gardening: what could be causing these holes in the grass ?, 1 by jo25

jo25 wrote:
Can anyone suggest what bug or creature might be causing these perfectly circular holes in my grass bed please? They are about 6-8 inches deep, half and inch or so in diameter, and there are quite a lot of them scattered over the small lawn area, which is fairly soft sandy soil, located 20 minutes from Melbourne city. No sign of any creatures, even when I've tried to check at night with a spotlight, and I doubt if they are cicadas, as the holes have been apearing for several months now. I also doubt that they are made by funnelweb spiders - I certainly hope not, and there's no web activity around the holes. The holes would appear to be empty. It's as if someone has gone around poking a round stick in the ground at irregular intervals.