strange soil deposits
United Kingdom 
I have dark brown to black circular soil deposits around my garden and I don't know what is causing them. They look a bit like the spirals that sand worms make on the beach. Does anyone know what is causing this?
3 Oct, 2008
Answers
Yep I think they're worm casts as well ... You will find them a lot on the lawn as well as beds. Stiff brush on dry ground. If you mow the lawn and the ground is a bit damp then the worm casts get flattened and the lawn takes sa while to recover. Little worms are good for your garden as they aerate the ground and at the moment they are taking leaves down underground eating them and passing them out as worm casts so don't worry.
If they are sandy mounds between cracks they are ants!!
4 Oct, 2008
Thanks for your answers. I think this must be what they are!
6 Oct, 2008
Are you sure they are not normal garden worm casts?
If they are just brush them away with a stiff broom.
This is the time of year for them.
3 Oct, 2008