Question
i live in eastern Washington, zone 5. My entire lawn is lumpy with hard spots of dirt pushed up in it. They are ruining my lawn. The only thing I read that is close to this probelm is grub worms. Do other worms cause this problem? I also have a kind of clover that is spreading too. Can you give me some ideas?

Answer
Grubs munch the roots of Turfgrasses -- they do not physically move Soil and make lumps and bumps all over.  Perhaps you mixed this up with damage by Moles and Voles?

Some states -- Colorado for instance -- are known for such an active Earthworms that bumpy Lawns are the rule, not the exception.  Thing is, it's GOOD to have Earthworms.  These animals devour thatch and grass clippings, snack on organic matter, recycle nutrients and aerate the soil.  Aerating and Rolling the Lawn with a weighted cylinder will smooth out the surface.

Note that since worms are good for a lawn, you should mow as high as the mower can be set and leave the worms alone.

Regarding the Clover you have, if you can confirm this is real, all American Clover, you should know that having Clover in the Lawn is like building your own Nitrogen fertilizer factory.  Keep the Clover.  It's GOOD for your Grass.