Dozens of species dig in garden soil, but the most common culprits tearing up flower beds are squirrels, chipmunks, moles, voles, skunks, raccoons, rats, and ground-nesting insects. Each leaves a different kind of hole, and figuring out which animal is responsible usually comes down to the size, depth, and pattern of the damage rather than catching the digger in the act.
Squirrels and Chipmunks
If you find small, shallow holes scattered randomly through your flower beds, squirrels are the most likely suspects. Gray squirrels and fox squirrels dig golf-ball-sized holes a few centimeters deep to bury nuts, seeds, and acorns for later retrieval. They also dig up bulbs, especially tulips and crocuses, which they treat as a ready-made food source. The holes tend to appear in clusters during autumn, when squirrels are actively caching food, and again in spring, when they return to retrieve what they buried. You will often notice freshly disturbed soil with no mound beside it, because the squirrel pushes the dirt back loosely rather than piling it up.
Chipmunks create similar surface holes but also dig proper burrow systems with entrances roughly five centimeters across. These entrances are tidier than squirrel holes and often lack a visible dirt pile because chipmunks carry excavated soil away in their cheek pouches. If you see a clean, round hole near the base of a wall, stepping stone, or garden border, a chipmunk burrow is a strong possibility. Both squirrels and chipmunks are attracted to freshly turned, loose soil, which is exactly what a well-maintained flower bed offers.
Moles and Voles
These two animals are constantly confused with each other, but they dig for completely different reasons and leave very different evidence. Moles are insectivores. They tunnel underground hunting earthworms and grubs, and they rarely eat plants. Their signature is a raised ridge of soil running across the bed where a shallow feeding tunnel has pushed up the surface, plus volcano-shaped mounds of fine dirt where deeper tunnels vent to the surface. If your flower bed has what looks like a miniature mountain range running through it, moles are almost certainly at work underneath.
Voles, on the other hand, are small rodents that eat plant roots, bulbs, and bark. They create surface runways, which look like narrow trails worn through mulch or grass leading to small, round holes about three to four centimeters in diameter. Voles are a serious threat to ornamental bulbs. Research testing how various flowering bulbs hold up against vole feeding found that most specialty bulbs showed some resistance to damage, with tulips being the notable exception. Tulips were heavily consumed, while other ornamental bulbs were largely left alone.1HortTechnology. Relative Resistance of Ornamental Flowering Bulbs to Feeding Damage by Voles If your tulips keep vanishing underground without a trace, voles are the prime suspect.
The simplest way to tell the two apart: moles leave raised ridges and volcano mounds but do not eat your plants. Voles leave surface runways and small round holes, and your bulbs disappear. The damage to the flower bed looks different, and the solution is different too.
Skunks and Raccoons
Skunks and raccoons both tear up flower beds to get at grubs, beetle larvae, and earthworms beneath the surface. Their damage is distinctive because it is messy and often covers a large area overnight. Instead of neat little holes, you will find patches of soil and mulch that have been rolled back or scraped away in rough, shallow divots, sometimes with chunks of turf peeled up at the edges.
Skunk holes tend to be cone-shaped, about seven to ten centimeters in diameter, and three to five centimeters deep. The animal pokes its snout into the soil and uses its front claws to dig out a grub just below the surface. You may find dozens of these small cones scattered across a bed in a single night. Raccoon damage looks more chaotic. Raccoons have strong forelimbs and dexterous front paws, so they pull back larger sections of mulch or sod and leave a torn-up mess. If the damage is concentrated in areas where you have noticed white grubs in the soil, one of these two nocturnal hunters is probably responsible. Treating the underlying grub population is often the most effective way to stop both animals from returning.
Rats
Norway rats, the common brown rat found in urban and suburban settings around the world, are active burrowers. They dig tunnels for shelter, nesting, and escape routes, and flower beds with soft, loose soil and nearby cover are attractive locations. A rat burrow entrance is roughly six to nine centimeters wide, often found along the edges of beds near walls, fences, or dense plantings. Excavated soil is typically pushed out in a fan-shaped pile in front of the hole.
Lab research on Norway rat burrowing reveals that the behavior is deeply ingrained and varies by genetic strain. Some strains begin digging almost immediately when given access to a soil substrate, while others are much slower to start and produce shorter tunnels. In one study, certain strains showed significantly shorter burrowing latency and more digging activity, producing longer and more complex burrows, and most of those rats instinctively escaped into their burrows when startled by a loud sound.2Behavioural Processes. Defensive aspects of burrowing behavior in rats (Rattus Norvegicus): A descriptive and correlational study The takeaway for gardeners is that burrowing is a core survival behavior for rats, not something they do casually. If you have rat burrows in your flower beds, the animals are likely nesting there, and the problem will not resolve itself without action.
Rat burrows are sometimes confused with chipmunk burrows, but there are reliable differences. Rat holes are slightly larger, the soil around them tends to be greasy or stained, and you may notice a musky odor. Rat burrows also often have a secondary exit hole some distance away, which chipmunk burrows typically lack.
Armadillos
In the southern United States and increasingly in states farther north as their range expands, nine-banded armadillos are among the most destructive diggers in garden beds. They use their powerful claws to root through soil for insects, grubs, and invertebrates, leaving behind holes that range from a few centimeters deep to full excavations fifteen centimeters across and ten or more centimeters deep. Armadillo damage looks like someone took a trowel to your bed in a hurry. The holes are irregularly shaped and often appear in groups, because the animal moves methodically through an area, sniffing and digging every few steps.
Unlike squirrels or chipmunks, armadillos are not interested in your plants or bulbs. They are after soil-dwelling invertebrates. The damage to plants is collateral rather than intentional, but it can be severe. Armadillos are nocturnal, so most of this destruction happens while you are asleep, and a single animal can work through a surprisingly large section of a flower bed in one night.
Rabbits and Groundhogs
Rabbits are better known for eating foliage than for digging, but they do create shallow scrapes in soft garden soil, sometimes called forms, where they rest during the day. In flower beds, you may find a shallow oval depression in the mulch with a few droppings nearby. Wild rabbits also dig nesting burrows, though they typically choose spots at the edge of a bed or under a shrub rather than in the middle of open soil.
Groundhogs are a different story entirely. Their burrows are large, with entrances ten to fifteen centimeters across and substantial mounds of excavated dirt beside them. Groundhog tunnels can extend several meters underground and have multiple entrances. If a groundhog decides to set up its burrow system under or adjacent to your flower bed, the structural damage to the bed can be significant. The animal also eats a wide range of garden plants, so you may notice both digging damage and heavily browsed foliage.
Ground-Nesting Bees and Wasps
Not every hole in a flower bed comes from a mammal. Many solitary bees and wasps nest directly in the ground, and flower beds with sandy or well-drained soil are prime real estate. Roughly 70% of the approximately 30,000 known bee species and most flower-visiting solitary wasps nest underground.3The Canadian Entomologist. Evaluation of nest-site selection of ground-nesting bees and wasps (Hymenoptera) using emergence traps That is an enormous number of species, and many of them find cultivated garden soil perfectly suitable.
Ground-nesting bee holes are small, usually pencil-width or slightly larger, and often surrounded by a tiny mound of fine excavated soil. You might notice several in the same area, because some species nest in loose aggregations where dozens or even hundreds of individuals dig their own separate tunnels in close proximity. Despite the numbers, these bees are overwhelmingly docile. Solitary bees rarely sting unless directly handled, and their nesting activity is temporary, usually lasting a few weeks in spring or early summer.
Cicada killer wasps, which are large and intimidating, also dig in garden beds. Their burrow entrances are larger, roughly the diameter of a finger, with a conspicuous mound of kicked-out soil. These wasps look alarming but are not aggressive toward people. If you see large wasps hovering low over your flower bed and disappearing into holes, cicada killers are the likely residents. The digging can displace a fair amount of soil, but the wasps provide genuine pest-control benefits by hunting cicadas.
The honest advice for ground-nesting bees and wasps in a flower bed is to leave them alone if you can. They pollinate your garden, they do not damage plant roots, and they will be gone in a few weeks. If their location is truly problematic, keeping the soil surface consistently moist or adding a thick layer of mulch discourages new nesting because these insects prefer dry, bare, or sparsely covered soil.
How to Identify the Culprit
When you walk outside and find your flower bed torn up, the hole itself is usually your best clue. Here is what to look for:
- Hole size: Pencil-width holes are ground-nesting insects. Holes three to five centimeters across point to chipmunks or voles. Holes six to nine centimeters suggest rats. Anything over ten centimeters is groundhog, rabbit, or armadillo territory.
- Hole shape: Cone-shaped divots in clusters mean a skunk hunting grubs. Torn-up patches of mulch or turf suggest a raccoon. Clean, round tunnels indicate a burrowing rodent.
- Soil mounds: Volcano-shaped mounds of fine, powdery soil are a mole trademark. Fan-shaped piles of coarser soil at an entrance are rat or groundhog. Tiny rings of excavated soil around a small hole point to bees or wasps.
- Raised ridges: Visible surface ridges running through the bed without any open holes are shallow mole tunnels.
- Timing: Damage that appears overnight points to nocturnal animals like skunks, raccoons, rats, or armadillos. Daytime activity is more consistent with squirrels, chipmunks, and ground-nesting insects.
- Plant damage: If plants are uprooted but not eaten, the digger is after something in the soil, not the plant itself. If bulbs vanish and roots are gnawed, voles are the leading suspect. If foliage is clipped cleanly, rabbits or groundhogs are eating your plants rather than digging for insects.
A motion-activated trail camera aimed at the bed overnight is the most reliable way to confirm the culprit if you are still unsure. They are inexpensive and settle the question quickly.
Why Flower Beds Attract So Many Diggers
Flower beds are magnets for digging animals because gardeners unintentionally create ideal conditions. The soil is loose, rich in organic matter, regularly watered, and full of earthworms and grubs. That combination is essentially a buffet sign for insectivores and a luxury apartment listing for burrowing rodents. Mulch provides cover for voles and runway material for their surface trails. Freshly planted bulbs are easy for squirrels and voles to locate by smell. Dense plantings provide shelter and concealment.
Research on how digging animals interact with soil shows that even small excavations can persist for a long time. One study found that over 75% of simulated animal digging pits were still visible after two years, and the pits altered soil temperature significantly, reducing the daytime temperature range by up to 25°C compared to the undisturbed surface.4PubMed Central. Effects of digging by a native and introduced ecosystem engineer on soil physical and chemical properties in temperate grassy woodland In a natural ecosystem, that micro-habitat change benefits seed germination and moisture retention. In your flower bed, it means that old holes do not simply fill in on their own, and they can change the conditions around nearby plants in ways you might not expect.
Practical Ways to Protect Your Beds
The right approach depends on what is doing the digging, which is why identification matters so much. A few strategies apply broadly:
- Hardware cloth: Laying a sheet of galvanized hardware cloth with half-inch mesh just below the soil surface, or lining the bottom and sides of a planting hole with it, physically blocks squirrels, chipmunks, and voles from reaching bulbs. This is one of the most reliable defenses for bulb plantings.
- Grub control: If skunks, raccoons, or armadillos are the problem, reducing the grub population in the soil removes their incentive. Beneficial nematodes or milky spore applied to the bed target grub larvae without harming plants.
- Mulch management: A thick layer of coarse mulch discourages ground-nesting bees and wasps, which prefer bare or lightly covered soil. Conversely, heavy mulch can provide cover for vole runways, so the right mulch strategy depends on your local pests.
- Bulb selection: Since tulips are particularly vulnerable to vole feeding while most other ornamental bulbs show resistance, substituting daffodils, alliums, fritillaries, or grape hyacinths in areas with known vole pressure can sidestep the problem.1HortTechnology. Relative Resistance of Ornamental Flowering Bulbs to Feeding Damage by Voles Daffodils contain alkaloids that make them unpalatable to most rodents, and alliums have a pungent taste that squirrels and voles avoid.
- Fencing and barriers: For larger animals like groundhogs and rabbits, a low fence buried ten to fifteen centimeters into the ground and extending sixty centimeters above it is effective. The buried portion prevents digging under. For rats, sealing gaps along walls and removing nearby harborage reduces pressure on the bed.
Repellent sprays based on castor oil, capsaicin, or predator urine are widely sold but produce mixed results. They need frequent reapplication, especially after rain or watering, and animals often habituate to them over time. Physical barriers and habitat modification tend to be more durable solutions.
When Digging Is Actually Good for the Garden
Not all animal digging in a flower bed is harmful. Earthworm activity, beetle larvae cycling through the soil, and ground-nesting bee tunnels all improve soil aeration and drainage. Even larger animals contribute to soil health in ways gardeners sometimes overlook. The excavation pits created by digging mammals can trap organic matter, retain moisture, and moderate soil temperature extremes, with summer pit temperatures measured at roughly 12°C cooler than the surrounding surface during the hottest part of the day.4PubMed Central. Effects of digging by a native and introduced ecosystem engineer on soil physical and chemical properties in temperate grassy woodland
Ground-nesting solitary bees are among the most effective pollinators you can have in a garden. If a patch of mining bees sets up in a corner of your flower bed, the pollination boost to nearby plants during their active weeks can be substantial. The small holes they leave close naturally once nesting season ends. Tolerating a bit of cosmetic disruption from beneficial diggers often pays dividends in garden health that you would otherwise need to supply artificially through amendments, aeration tools, or purchased pollinators. The animals worth evicting are the ones eating your plants or creating structural damage. The rest are doing work you would have to do yourself.