Worms don't really cause much damage, apart
from the small mounds of soil they leave
on the surface of your lawn. Theses are
called worm casts. However they can attract
moles and if that happens you could
find mounds of soil a thousand times bigger
than the worm cast. Worm killers can be
purchased from your local gardening store.
If you don't like using chemicals then simply
wait till the worm casts dry out one sunny
day and brush off.
The best way is to avoid worms is too keep
leaves and debris of the lawn by regular
Try not to use organic materials such as
bone meal and dried blood on your lawn as
this is the worms favourite diet.
If all fails remove your lawn!