Hopefully the attached picture will show the problem. It looks as though something has just been poking holes everywhere. No worm casts, just clean holes slightly wider than a pencil width. Any ideas ?
Could be mice, have you got any bulbs down there?
or ants for the green woodpeckers to hunt?
It could be something tunneling out-rather than something tunneling in
Yes, I agree - looks like worm holes to me, too small for mice, too regular for birds.
hover flies by the looks of things,they are good for the garden,or bumble bees but they are normally single on their own,I take it they are small holes.
There are solitary bees that nest in colonies.
have you put a spade into the area around the holes to try and find the culprit if any
Haven't had a dig around yet, but they remind me of the breathing holes you see on wet sand sometimes. They're all over a raised bed about 6 x 12ft. No paw prints or footprints or mess. Looks more like someone got a bamboo cane and poked the soil with that.