Where are you? I've never heard of or seen anything like that. Do you have some pictures?

To all about the earthworms...

Yes infestation can exist. There are many sites on the subject with Canadian golf courses suffering as well.

Paul, thanks....but we do not cut our grass lower than 2 1/2 go 3" at any time and bag the clippings always. We don't like to spread weeds around and this works. I was asking more along the lines of whether clay attracts more worms or not. I think I will add organics, aerate and pray for no more rain.

Cheers!

KG, we keep running into each other! Worms only exist where there is adequate food. They'll love the compost! My guess is that your soil is compacted clay, and they are coming up for air when the ground is water-soaked. Try core-aeration when the soil dries out. This removes plugs and should make a big difference.

As for mowing lawn, leave the clipping on the soil. Weeds only spread if they have gone to seed, and that is the reason for mowing LONG but mowing OFTEN. Compost (or fertilizer) will not be needed as often since lawn essentially makes its own. If THATCH is a problem, again, you need to aerate. Thatch is DEAD grass, not grass clippings; and it too is common in compacted soils.