Holes in lawn

Asked May 26, 2016, 10:59 PM EDT

I have hundreds of these all over my lawn. They are most noticeable after watering. What is causing them?

Deschutes County Oregon integrated pest management horticulture

1 Response

Thanks for the pictures. These look like earthworm/night crawler holes. The little clumpy particles around the holes are the frass (poop) which contributes good nutrients to the soil for your lawn. There is no chemical management for earthworms in lawns as they are beneficial. If the lawn starts to get too clumpy you can rake the piles of frass to redistribute them.