Determining what causes holes in lawn and landscaping can be a challenging endeavor for any homeowner. The size of the hole, the presence of excavated dirt, and timing of activity are all good clues to consider. Recently, I had several holes along my driveway and sidewalk that perplexed me. I’m no stranger to holes in my yard. I’ve been combating moles in my yard (we will save that for another post) and had recently observed dead mice and shrews in my driveway. I also have many chipmunks and gray squirrels around the yard. All of these can make holes of one type or another. However, these new holes looked different. They were clearly a tunnel/burrow with an entrance of 1.5 inches. Squirrels dig holes to bury/dig nuts or to feed on small plants. Chipmunks make one and half inch holes but they carry the cast soil away in their mouths which results in a less conspicuous hole. Shrews and voles will excavate holes and tunnels, but these looked different. Voles usually are found in areas with overhead cover such as densely planted landscaping beds, areas with ground ivy or similar plants, and beds with think mulch. These holes were exposed far from cover. So what were they?
It so happens I was at a colleague’s house recently and he mentioned all the cicada killers he has around the house. He literally had dozens of holes in areas with exposed soil just like the ones I observed at home. To my delight, I finally had the answer to my question.
Cicada killers are large wasps, but unlikely to sting. Purdue’s Department of Entomology has more on cicada killers here.
Brian MacGowan, Extension Wildlife Specialist
Department of Forestry and Natural Resources