Question
QUESTION: Hello!  I have a few small perfectly round holes about the size of a golf ball, and small "bumps" (way too many to count) in my backyard.  With every step I take there are at least two bumps under each foot. Looking at the lawn you can't see the bumps as they under the grass.  The bumps have increased considerably in the six years that I have lived here. I live in New York state in the West Point area.  I never see anything that could be living under my lawn.  I know a raccoon walks through my yard a few nights a week on its way to where ever it goes at night. I have had a few mice in my house over the years, but my cats took care of them and I do not have any more mice.  The cats are house cats and do not go outdoors.  I use Scotts fertilizer on the lawn 4 times a year and try to water the lawn at once a week in the summer.  I had grubs in the front yard but never in the back yard.  I bought grub control from Scotts and that got rid of them. I am trying to give you as much info as I can so please excuse me if I give you way too much.  Any help that you can offer would be greatly appreciated.  Thank you, Catherine

ANSWER: Never too much information. :)  You didn't say if the holes went anywhere? Do they stop? If they disappear and actually go somewhere, my first guess would be chipmunk.

You can visit http://www.icwdm.org/Inspection/Default.asp  and use our inspection key to help narrow down the culprit. Visiting will also help you see the type of information I need to help make a diagnosis.

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QUESTION: Chipmunks!!  Disney's Chip and Dale living in my backyard!!  Okay, I can live with that.  In answer to your question if the holes went any where - yes, they do.  How far, I don't know. When I put water down the hole with my garden hose, the water disappears.  I went to the site you suggested to view the inspection key.  The holes I have look similar to the chipmunk hole in regard to the size but mine do not have any dirt around it - they are just round holes in the grass - except for one spot.  There is one hole that is under an extension that I put on the downspout from the gutter to draw rain water away from the house foundation - the grass has stopped growing under the extension.  I had put some small rocks over the hole to see what would happen and a few days later I could see that the hole was enlarged a bit to get around the rocks.
I was thinking of aerating my yard and maybe at some point roto-tilling the lawn to reseed or lay sod.  If I do either of these would I hurt Chip and Dale?
Thanks so much, Catherine

Answer
aerating your lawn shouldn't be a problem for the chipmunks. As for the dirt, dirt is frequently absent around their holes. Presence of dirt depends on the situation.
My one concern is why you haven't seen any chipmunks. THey should be quite active right now getting ready for winter.