Why would anyone want to get rid of worms?
Worms do NOT leave cement like casings, in fact they leave composted nutrients for your plants that can readily use it.
If gardeners would allow mother nature to work its wonders, it would be better for the enviornment, and for us all.
If you feel that you want to get rid of them, any gardner would love to have them. Stick up a sign and you will have a lineup of horticultural buffs at your door.