They do no harm but if they annoy you soaking the area drowns them and they get the hint to move on. Stick the hose on with the wide spray over the area they are seen most and that will help.

Thanks for replying,its been asked a few times (since I asked and didnt get any answers at the time) with some sugestions.I brushed the soil mounds off,remembered reading that somewhere last year,and for the time being anyway they seem to have gone.two years ago my lawn looked a real mess there were mounds of earth all over it,and I wanted to nip it in the bud early on.