Burrowing lawn insects...
By Marymaryv
United Kingdom 
Checked my front lawn a couple of days ago and thought I had worm casts on top but on closer inspection found that there were little volcanic shaped mounds with flies going in and out!! Covered the holes over but by next day they were all open again. No luck with internet research so far..Can you help??
10 Apr, 2009
Answers
Ah, thanks owdboggy, how cute!!
10 Apr, 2009
Thanks for the information Owdboggy. Lot less worried now!!
Still dont think they are 'cute' though!!
11 Apr, 2009
Previous question
Sounds like mining bees! Very useful non-stinging insects. They lay their eggs in holes in the lawn and the larva develops in the little chamber at the bottom. Ignore them and in a few weeks time the chamber will be sealed for the larva to develop into a bee for next year.
10 Apr, 2009