Holes in backyard
From a photo it is hard to see the correct proportion of the holes in contrast to the rest of the yard. Many forms of wildlife can produce holes similar to those pictured above. Insects are the most likely troublemakers but Clemson University discusses other possible culprits:
If you are very observant, you may see small holes as if something was poked into the ground, but no mounds or loose soil. These are probably caused by birds looking for food.
If the soil in your yard has a healthy population of earthworms, you may find 1-inch high piles of small, granular pellets of soil. These castings were passed through the body of earthworms the night before and were brought to the surface as tunnels were cleared. They are more common in spring and fall when soil moisture and temperatures are conducive to earthworm activity. There is usually no hole in the top.
There are many insects that spend the winter in the soil, during which time they transform from a larva into an adult. In the spring and early summer, especially after a rain, you may see nickel-size holes caused by their emergence. These holes may be surrounded by small mounds of loose soil and fecal pellets. Examples include cicadas and June beetles.
There are also insects that prefer to live in the ground during their adult stage. Many bees, for example, are solitary and will dig cylindrical tunnels in loose soil as they create chambers for egg-laying. These holes are typically between ¼-and ½-inch wide and are found where vegetation is sparse. The entrance may be surrounded by a mound of loose soil as high as 2 inches.
Feel free to contact our office if you have other questions.
Let me know if I can help you further!
Jefferson County Cooperative Extension Service
200 Juneau Drive
Louisville KY 40243