i have a flower garden in the front of my house next to a long slab of pavers. there are a few perennials coming up, the mostly there is a lot of plain dirt…nothing growing in it, as of yet. during the past 1 1/2 wks i have noticed cone-shaped holes in the dirt…about the size of a dime…some a larger. i tried covering them up with dirt…next moring they were back again. tried again several times…keep reappearing. put some powdered sevin in each hole…about 20 holes…next day holes ae back…bigger and deeper. they are all (separate holes…some quie close to each other, but they do not connect) i then put in some liquid bug killer…don't know what kind…label says it's good for many diff bugs…incl. bees. (i have carpenter bees in my mail box post.) i am anxious to see what happens and what could be causing these holes. can these holes be made by the carpenter bees? (holes are perfectly round..about 1/2" deep…circumference of a dime) what other insect coud be making these holes? i also get hump back crickets in my basement….could the holes be from them? bugs are driving me crazy!!!!!!!!!!!!!!!!!!!!!!
At this point I'm not so certain you have any insect involved so I would refrain from all the chemical treatments till you are 100% sure. In fact it's more likely an animal that's doing all the digging. In my experience, seeing holes like this is usually the result of past or present tunneling from an animal like a MOLE or a VOLE. Both like to live in the yard and both tunnel. When tunneling, they will sometimes get too close to the surface and these weak spots will many times end up breaking through to the surface in the form of little holes. This could be happening where animals were once active and over time the eroded soil is finally showing the impact of their digging.
What's more likely involved is and active Vole. As explained in our VOLE CONTROL ARTICLE, this animal is very active in the spring and during this time will be digging lots of new tunnels with "ports" or small holes throughout their network. Coincidentally voles love gardens – especially flower beds. My money is on this little guy as they are quite small and the holes they create fit your description to a tee.
For now I suggest filling in all the holes and seeing if they reappear. Keep good records and information on where all the "current" activity is located and if needed, do some of the vole control treatments we have posted in our article and I'm sure you'll catch the varmint's'. Here are direct links for the information posted above: