Holes in Mulch Beds: Who's Digging Through Your Mulch?

Disturbed mulch usually comes down to a simple distinction: mulch flipped and scattered on top means squirrels or birds foraging through it, while an actual hole punched down into the soil beneath means a chipmunk, rat, or cat. Squirrels and chipmunks are the everyday culprits; the pattern of the mess tells you whether you're looking at snacking, caching, burrowing, or a litter box.

Most likely causes

  • Squirrels — small pits dug and refilled, mulch flicked aside, worst near nut trees and bird feeders
  • Chipmunks — a clean 2-inch hole descending through the mulch into soil, no dirt pile
  • Birds — mulch flipped onto the lawn or walkway in a band along the bed edge, no real holes
  • Rats — a worn burrow entrance under dense shrubs or against a wall behind the mulch
  • Cats — shallow scrapes with mulch raked back over buried droppings

Compare the possible causes

Possible cause Key signs When it happens How likely
Squirrels Scattered small excavations a few inches wide, some refilled into little humps, with mulch flicked outward and occasional shell or husk litter Frantic in fall during caching season; retrieval digging continues through winter and spring Very common
Chipmunks A neat, round, 2-inch hole that passes through the mulch into the soil and keeps going, with no excavated dirt anywhere Spring through fall; beds along foundations, walls, and walkway edges are favorites Common
Birds tossing mulch Mulch thrown out of the bed onto adjacent lawn or pavement, in a band along the bed edge, with shallow scratched patches but no true holes Year-round; most vigorous in spring and fall when leaf litter invertebrates are abundant Very common
Rats A 2- to 3-inch burrow entrance with kicked-out soil, tucked behind shrubs or against a wall at the back of the bed, with droppings or a worn path along the edge Any season, wherever feeders, garbage, compost, or pet food are close by Less common
Cats Shallow scraped hollows with mulch and soil raked back over them, recurring in the same open, fine-textured patches, with buried waste beneath Year-round; fine-shredded or aged mulch in dry, quiet corners gets the most use Common

Visual clues to check

  • Ask where the mulch went: flipped onto the lawn or path means birds; flicked in place means squirrels; undisturbed around a clean hole means chipmunk
  • Check whether the hole reaches soil: surface rummaging is foraging; a tunnel descending into the ground is a burrow
  • Look for cover-up: material raked back over a shallow scrape, with buried droppings, is a cat
  • Inspect the back of the bed against the wall for a worn entrance with excavated soil — the rat position
  • Note the schedule: mess appearing during daylight points to birds and squirrels; overnight points to rats, cats, or heavier wildlife
  • Scan for food debris: nut shells and husks (squirrels), seed hulls under a feeder (birds and rodents), nothing at all (cats and chipmunks)

The causes in detail

Squirrels

To a squirrel, a mulch bed is a bank vault with a soft door. They bury nuts, sunflower seeds carried from your feeder, and stolen bulbs an inch or two down, then return repeatedly to check and move deposits — which is why the same bed gets re-dug all season. The holes are shallow, randomly placed, and often half-refilled. Annoying, endlessly renewable, and essentially harmless to established plants.

Chipmunks

Where squirrels dig pits, chipmunks dig real estate. A chipmunk burrow entrance in a mulch bed is unmistakable once you know the look: clean, vertical, and dirt-free, because the excavated soil leaves the site in cheek pouches. Foundation beds are prime territory since the burrow gains a roof of landscape fabric, roots, or slab edge. One tidy hole is normal; several along a foundation or retaining wall are worth monitoring.

Birds tossing mulch

Robins, towhees, thrashers, sparrows, and — where flocks roam — wild turkeys all forage by kicking and flinging mulch aside to expose the insects, worms, and seeds underneath. The result is a mysteriously self-emptying bed edge: mulch on the sidewalk every morning, no holes, no tunnels, no missing plants. It's the easiest diagnosis on this list to confirm, since the work happens in daylight — one morning coffee by the window usually catches the crew.

Rats

Dense foundation plantings over a soft mulch bed give rats exactly what they want: covered travel routes and easy digging with a structure to burrow against. Unlike a chipmunk's clean hole, a rat burrow shows excavated soil at the mouth and heavy wear from nightly use, and it hides at the back of the bed rather than out in the open. Capsule-shaped droppings along the wall confirm it — and move the situation from landscaping annoyance to pest control priority.

Cats

Outdoor cats treat loose, fine mulch like litter. The tell is the cover-up: unlike foragers, cats rake material back over the spot, and a trowel check turns up droppings just below the surface. Beyond the smell and the gardening unpleasantness, cat feces can carry toxoplasmosis, so wear gloves working in beds cats use. Switching to coarse bark nuggets or pinning down chicken wire under a thin mulch layer usually ends the visits.

When to worry

  • A burrow entrance with excavated soil and droppings at the back of a foundation bed — treat as rats until proven otherwise
  • Multiple chipmunk holes along a foundation, stoop, or retaining wall footing
  • Digging paired with plants wilting or disappearing, which suggests root damage or bulb theft beyond surface mess
  • Cat waste accumulating in beds where children play or near vegetable plantings
  • Mulch disturbance plus gnaw marks on drip lines, wiring, or the base of siding

What to do now

  1. Watch the bed for one morning and one evening before doing anything — most mulch diggers are easy to catch in the act
  2. Rake foraged mulch back and accept some bird traffic; they're eating the very grubs and insects you don't want
  3. Move bird feeders away from beds or add trays — spilled seed is the engine behind squirrel, chipmunk, and rat interest
  4. Pin chicken wire or hardware cloth flat over freshly planted or frequently raided areas and re-cover with a thin mulch layer
  5. Switch fine mulch to coarse bark nuggets or add a gravel edge strip to discourage cats and casual digging
  6. Keep mulch no more than 2 to 3 inches deep and pulled back from stems and siding, which reduces rodent cover
  7. If you find a worn burrow with droppings, or any sign of rats, contact a licensed pest control professional rather than setting bait among the shrubs

What not to do

  • Don't scatter rodent bait or snap traps loose in a mulch bed — pets, songbirds, and children reach them first
  • Don't use mothballs as a repellent; it's illegal off-label, toxic to pets, and doesn't work
  • Don't handle cat or rodent droppings barehanded while working the bed
  • Don't pile mulch deeper to 'bury the problem' — deep mulch is rodent habitat and invites stem rot too
  • Don't seal a chipmunk or rat hole while it's active; confirm vacancy first or you'll be re-digging it out of frustration weekly

Think you know the suspect?

These animals commonly cause this clue — see their full sign profiles:

Frequently asked questions

What animal throws mulch out of my flower beds every day?

Daily mulch on the lawn or sidewalk, with no real holes in the bed, is almost always birds — robins, towhees, thrashers, and other ground foragers kick mulch aside to expose insects underneath. It happens in daylight, so a few minutes of watching in the morning will usually show you exactly who's doing it.

Why is there a perfectly clean hole in my mulch with no dirt around it?

That's the chipmunk signature. They excavate burrows from below and carry the soil away in their cheek pouches, so the entrance — usually about 2 inches across — looks drilled rather than dug. Squirrel and rat digging both leave loose material at the surface; only chipmunks leave nothing.

Does mulch attract rats?

Mulch alone doesn't feed rats, but deep mulch under dense shrubs gives them cover and easy burrowing, and it becomes attractive when food is nearby — birdseed, pet food, garbage, fallen fruit, or compost. Keeping mulch under 3 inches, thinning ground-hugging shrubs, and eliminating those food sources removes most of the appeal.

How do I keep squirrels from digging in my mulch beds?

You manage it rather than end it. Physical mesh — chicken wire pinned flat under a thin mulch layer — protects the areas you care about, moving or tray-feeding bird feeders removes the seed subsidy, and coarse nugget mulch is less fun to dig than shredded. Repellent sprays wash out and rarely change squirrel behavior for long.

Related yard clues

Yard Holes Holes in Flower Beds Overnight? Meet the Night Shift Flower beds dug up overnight are almost always animals hunting food, not making homes: skunks and raccoons dig for grubs and worms in the soft soil, squirrels bury and retrieve nuts, cats use loose beds as litter boxes, and across the South armadillos root through beds nose-first. Each leaves a different style of hole, so one careful morning inspection usually names your visitor. Read the guide → Yard Holes Holes Around Tree Roots: Squirrels, Voles, or Wasps? Holes at the base of a tree usually belong to squirrels burying and retrieving nuts, voles working the mulch line, or rats denning in the sheltered pocket under the root flare — and sometimes to nothing living at all, since decayed old roots leave open channels in the soil. The one to identify before you get close is a yellowjacket colony nesting in a hollow among the roots. Read the guide → Yard Holes Small Holes in Yard With No Mound: What's Digging? Small holes in your yard with no dirt mound are usually caused by squirrels, chipmunks, foraging birds, earthworms, or ground-nesting insects. The size of the hole, how deep it goes, the time of year, and whether the damage appeared overnight can narrow down the cause quickly. Read the guide → Yard Holes Holes Near Your Foundation: Causes and When to Act Holes right along a foundation usually come from chipmunks, Norway rats, or voles, all of which like the shelter a house wall provides — but water pouring from downspouts and settling backfill soil carve foundation-line holes too. Sorting burrow from washout matters, because a rat burrow against the house is the one that needs fast professional attention. Read the guide →

Still not sure? Compare with these clues

Mushrooms & Growths Orange Fungus in Mulch: Stinkhorns, Slime, and Siding Spots Orange growths in mulch are almost always fungi feeding on the wood itself — most often stinkhorns (the smelly orange fingers), orange peel fungus, or a slime mold. They're harmless to plants and people who leave them alone. The one mulch fungus that costs money is artillery fungus, which shoots tar-like black dots onto siding and cars. Read the guide → Mushrooms & Growths Slime Mold in Mulch: The Gross-Looking Blob That's Harmless A foamy yellow, tan, or orange blob spreading across your mulch is almost certainly a slime mold — most often the species nicknamed 'dog vomit slime mold.' Despite the revolting look, it's completely harmless to plants, pets, and people, it usually rides in on fresh hardwood mulch, and it needs no treatment: rake it out, hose it apart, or just let it dry up on its own. Read the guide → Animal Droppings Tubular Droppings in the Garden: Raccoon, Opossum, or Skunk? Tubular droppings in a garden bed most often come from raccoons, opossums, or skunks raiding for produce, grubs, and insects — though garter snakes and even toads leave surprisingly substantial droppings too. Blunt ends and berry seeds point to raccoon, tapered curves to opossum, and a crumbly texture full of shiny insect parts to skunk. Because raccoon droppings can carry roundworm eggs, droppings in a food garden also raise a produce-safety question worth taking seriously. Read the guide →