Lawn Mounds vs. Girdled Bark: Moles and Voles Aren't the Same Problem

A cone-shaped mound of loose soil pushed up overnight in the lawn, and a ring of bark chewed away at the base of a young fruit tree, get blamed on "moles" interchangeably all the time. Clemson Cooperative Extension's guide on telling the two apart starts with the most basic correction: moles and voles aren't even the same kind of animal. Moles are insectivores, not rodents at all — more closely related to shrews than to mice. Voles are rodents, and look like a stocky, short-tailed field mouse. That taxonomic split carries through to diet, damage, and the right way to actually address either one.

What each one actually looks like

Clemson describes moles as having no visible external ears, small or vestigial eyes, a body typically 4 to 7 inches long, and large, paddle-shaped front feet with prominent claws built for digging — features that make sense for an animal that spends almost its entire life underground. Voles, by contrast, look like an ordinary mouse: small beady eyes, small ears, a short tail, and soft gray fur, and unlike moles they're regularly seen moving around above ground in grass and ground cover rather than staying hidden underground.

The diet difference that explains everything else

This is the single most commonly misunderstood fact about either animal: moles don't eat plants at all. Iowa State University Extension identifies earthworms as a mole's main food source, and Michigan State University Extension quantifies the diet more precisely — roughly 80 percent earthworms, with the remaining 20 percent made up of soil insects and grubs. A mole tunnels through a lawn hunting prey, not because it's after grass roots or bulbs. Voles are the opposite: Clemson describes them plainly as vegetarians that eat the roots and stems of plants, and the Internet Center for Wildlife Damage Management (hosted by the University of Nebraska-Lincoln) describes vole gnawing as leaving irregular bark and cambium damage at varied angles around the base of trees and shrubs, particularly in winter when other food is scarcer — distinct from the cleaner, angled cuts left by rabbit feeding on the same plants.

Why the two are easy to mix up on the same property

University of Maryland Extension notes a detail that explains a lot of the real-world confusion: voles will use existing mole tunnels to reach and feed on plant roots, meaning a single lawn can genuinely host both animals' damage at once — raised mole ridges from the original tunneling, plus root damage from voles exploiting those same tunnels afterward. The two forms of damage look and function differently even when they're happening in the same patch of ground, which is exactly why blaming one visible symptom (a mound, a girdled trunk) on the wrong animal is such a common mistake.

Reading the damage correctly

Mole activity produces raised ridges running just under the lawn's surface, along with the classic volcano-shaped mounds of loose soil pushed up at intervals as the mole excavates — both confirmed by Clemson's guidance. Vole activity looks different: visible, narrow surface runways worn through grass, connecting burrow entrances, without the volcano-shaped mounds moles produce. Vole populations can also expand quickly once established — University of Nebraska Extension and University of Kentucky Extension both describe meadow and prairie voles in field conditions producing roughly 5 to 10 litters a year with 3 to 5 young per litter, and University of Idaho Extension notes vole populations cycle through minor peaks every 4 to 6 years and larger population surges roughly every 10 to 12 years.

Why the fix for one does nothing for the other

Because moles primarily eat earthworms rather than grubs, Illinois Extension and Iowa State Extension both point out that grub-killing insecticides are a frequently ineffective mole control strategy — killing the lawn's grub population doesn't remove the earthworms a mole is actually after, so the mole has little reason to leave. Trapping is the extension-recommended primary method for actually reducing mole activity. Vole control runs on an entirely different approach, since the real risk with voles is genuine plant damage rather than cosmetic lawn disruption: University of Maryland Extension recommends 18-inch-high cylinders made of quarter-inch hardware cloth around the trunks of young or vulnerable trees, extending 2 to 3 inches below the soil line, along with avoiding mulch piled directly against a trunk or packed under shrubs, since it gives voles cover right where the most damaging gnawing happens.

• Moles are insectivores (not rodents) that eat mostly earthworms and some soil insects — they tunnel to hunt, not to eat plants.
• Voles are rodents that eat grass, roots, bulbs, and bark, and are the ones responsible for girdled tree trunks, especially under winter snow cover.
• Mole damage shows up as raised ridges and volcano-shaped mounds; vole damage shows up as visible surface runways and gnawed bark, with no mounds.
• Voles sometimes use abandoned mole tunnels to reach plant roots, so a single lawn can genuinely show both animals' damage at once.
• Grub-killing insecticides often fail against moles since earthworms (not grubs) are their main food; vole protection instead relies on buried hardware cloth around trunks and keeping mulch away from the base.

Lawn mounds and girdled bark call for genuinely different responses, and misidentifying which animal is responsible usually means treating the wrong problem. A free Sevacorp inspection can help confirm which one is actually present on a property before deciding what to do about it.

• Sources:
• Clemson Cooperative Extension, Home & Garden Information Center — "How to Tell the Difference Between Moles and Voles" — https://hgic.clemson.edu/factsheet/how-to-tell-the-difference-between-moles-voles/
• Iowa State University Extension, Yard and Garden — "Will Applying Insecticides to Kill Grubs Help Control Moles?" — https://yardandgarden.extension.iastate.edu/faq/will-applying-insecticides-kill-grubs-help-control-moles
• Iowa State University Extension, Yard and Garden — "Moles in the Lawn: Control" — https://yardandgarden.extension.iastate.edu/encyclopedia/moles-lawn-control
• Michigan State University Extension — "Reduce Lawn and Garden Damage Caused by Moles, Skunks, and Raccoons" — https://www.canr.msu.edu/news/reduce_lawn_and_garden_damage_caused_by_moles_skunks_and_raccoons
• Internet Center for Wildlife Damage Management (University of Nebraska-Lincoln) — "Vole Damage" — https://icwdm.org/species/rodents/voles/vole-damage/
• University of Illinois Extension — "Choose Treatment Properly for Moles" — https://extension.illinois.edu/blogs/ilriverhort/2016-03-20-choose-treatment-properly-moles
• University of Maryland Extension — "Voles" — https://extension.umd.edu/resource/voles
• University of Nebraska-Lincoln Extension — "Controlling Vole Damage" — https://cms.unl.edu/ianr/extension/wildlife/sites/unl.edu.ianr.extension.wildlife/files/media/file/controlling-vole-damage.pdf
• University of Kentucky Cooperative Extension — "Voles" (FOR172) — https://publications.ca.uky.edu/files/FOR172.pdf
• University of Idaho Extension — Vole IPM page — https://uidaho.edu/extension/ipm/ag-pests/other/voles