How do you know if Grubs are eating your grass roots?

If grubs are eating your grass roots, you should be able to grab a bunch of grass and pull up with the result that the grass pulls away from the dirt in a similar manner to grabbing your indoor carpet and pulling it up away from the floor.

If you dig out a little section of grass, it will look as if the grass was lying on a nice, fine layer of peat moss, except it isn't peat moss . . . It's chewed up roots.