What is digging holes under my bird feeder?

The short answer

• Measure the opening and look at the soil. A round hole about 2 inches across with no mound is a chipmunk, a vole, a rat or a squirrel's cache pit. A 10 to 12 inch hole with a big mound is a groundhog.
• Cone-shaped holes 3 to 4 inches across that appear overnight are a skunk or a raccoon digging for grubs, not for seed. Shallow pits 1 to 3 inches deep and 3 to 5 inches across, dozens in a night, are an armadillo in the Southeast.
• Armadillos do not come for the seed. UGA puts their diet at often more than 90 percent insects, grubs and earthworms, so moving the feeder will not stop them.
• Rodents come for the spill. Chipmunks, voles, rats and squirrels dig under a feeder because of the seed on the ground: hulled seed, a catch tray and raking before dark end it.
• Small poke holes with no soil at all are birds feeding. Nickel-size holes with a little mound in spring are insects emerging. Neither needs fixing.

Measure the hole and look at the soil around it. A round opening about 2 inches across with no soil piled beside it is a chipmunk, a vole, a rat or a squirrel's cache pit, and all four are there for the seed. Cone-shaped holes 3 to 4 inches across that appear overnight are a skunk or a raccoon digging for grubs. Dozens of shallow pits in a Southern lawn are an armadillo, which is not after your seed at all. A hole a foot wide with a mound of dirt in front is a groundhog.

That split matters more than the animal's name. The usual assumption is that anything digging under a feeder is digging for seed, so the fix is to move the feeder. That is right for the rodents and wrong for the grub diggers, and moving the feeder six feet only moves the argument.

The hole table#

Go out in the morning before you rake. Measure the opening, not the disturbed turf around it, and press a stick in to see whether it is a pit or a tunnel. Figures from ICWDM, Clemson Extension, UC IPM, Penn State, UGA and UF/IFAS.

Moles are not in the table because they leave raised ridges and volcano-shaped mounds, not open holes. Birds are in it because people blame them least: Clemson calls the small pokes with no loose soil "probably caused by birds looking for food," and on a Florida lawn the probers can be as big as the sandhill cranes under the feeder.

Four animals at 2 inches#

Squirrel. Clemson describes gray squirrel holes as typically 2 inches across, shallow, with no soil around them. ICWDM says gray and fox squirrels scatter-cache food around their home range and damage lawns "by burying or digging up nuts." Our reading: if you put out in-shell peanuts, the pits are squirrels hiding them. A shallow pit that ends, rather than a tunnel, is the sign. See squirrels.

Chipmunk. ICWDM puts the burrow entrance at about 2 inches with "no obvious mounds of soil," because the chipmunk carries the dirt off in its cheek pouches. Clemson puts it by stumps, buildings, brush piles or log piles. A chipmunk defends about 50 ft around its entrance and caches food in the burrow all year (ICWDM), so a hole within 50 ft of the feeder is very likely the one. See chipmunks.

Vole. UC IPM gives burrow openings of about 1.5 to 2 inches, Clemson 1 to 1.5 inches, and both agree there is no mound. The runway gives it away: ICWDM describes 1 to 2 inch trails cut into the grass between several openings, with vegetation clipped close. More on voles.

Rat. ICWDM describes active Norway rat holes as 2 to 3 inches wide, "clean of debris," with rat hairs at the entrance, by walls, fences and bushes. Clemson gives up to 3 inches. Droppings up to 3/4 inch long with blunt ends settle it, and the fix is the dusk routine on rats and mice.

If you still cannot tell, run ICWDM's tracking test: smooth a patch of flour on a board beside the hole overnight and read the prints in the morning.

Holes that appear overnight#

Clemson says skunk and raccoon digging "occurs at night." Both are hunting beetle grubs and other soil insects. ICWDM describes skunk holes as "small, 3- to 4-inch cone-shaped holes or patches of upturned earth," dug with precision, section by section, and notes that the digging generally stops after about 3 weeks because the food runs out.

The feeder still plays a part. University of Maryland Extension lists "bird seed/feeders" among skunk attractants, with pet food, trash and compost. The seed draws the skunk in and the grubs keep it digging. Cones clustered in the drop zone: rake before dark. Cones across the whole lawn: the lawn is the meal. Our skunks page covers the den and the law.

A raccoon is the one that rolls sod back in strips. ICWDM says raccoons "roll up freshly laid sod in search of earthworms and grubs," often night after night. If it has found the feeder too, see raccoons and what is emptying my bird feeder at night.

Armadillos dig for grubs, not seed#

ICWDM gives the holes as 1 to 3 inches deep and 3 to 5 inches wide, and UGA's circular says 1 to 3 inches deep and 3 to 5 inches long. UF/IFAS gives a fuller picture: one armadillo "may dig dozens of shallow holes 2-6 cm wide and up to 15 cm deep each night," which is about 3/4 to 2 1/2 inches across and up to 6 inches deep. It prefers moist soil, so watered lawns and beds take the worst of it.

The diet is the point. UGA says it "often consists of more than 90 percent insects, grubs and earthworms," and ICWDM gives more than 90 percent insects. UF puts insects at about 75 percent by volume, mostly beetles, with most of the rest other invertebrates. Either way the armadillo is in the soil, not the seed: none of the three sources lists seed as armadillo food. So:

• Cleaning up under the feeder will not stop the pits. Do it for the rodents.
• No repellent is registered. UF says no repellents, toxicants or fumigants are registered for armadillos.
• Traps rarely work with bait. UGA's trial caught 10 armadillos in 1,332 trap nights, and baited traps did no better than unbaited ones. UF found armadillos do not notice food until it is within a few feet. Place a trap at an active burrow or along a fence the armadillo follows.
• The law is lenient in Georgia. UGA says armadillos are not protected under Georgia wildlife regulations and "may be hunted or trapped year-round without limit." UF calls them invasive in Florida. In South Carolina, Clemson notes the state DNR does not allow trapped animals to be relocated off the property.

Wear gloves if you handle one. ICWDM and UF both note armadillos can carry the bacterium that causes leprosy.

Is it a groundhog?#

Penn State and ICWDM give the main woodchuck entrance as 10 to 12 inches, with a large mound of excavated earth the animal sits on to watch. Secondary entrances are dug from below and have no mound, so you may find those first. Clemson notes groundhogs are active in daylight. Seed on the ground is plant food to a woodchuck, and our groundhogs page covers the calendar for closing the burrow.

What to do once you know#

For the four small rodents, the seed is the reason, and for a groundhog it is a reason to stay, so take it away:

1. Put less on the ground. Sunflower hearts leave no hulls and little whole seed. The hull arithmetic is on seed waste and mess.
2. Retire the ground feeder for now. A ground feeder or an open platform tray is a rodent table until the holes stop.
3. Rake at dusk, not at dawn. Rats, skunks and raccoons work the ground at night.
4. Take away the cover. Feeders over mown lawn rather than ivy or a woodpile make voles, rats and chipmunks cross open ground. See where to put a bird feeder.

For the grub diggers, the lawn is the reason. Clemson says the most efficient time to treat grubs is early July, when they are small and near the surface. Seed that has sprouted in the holes is a separate story, told on what is growing under my bird feeder.

Where this page stops#

• Sizes overlap. These are typical sizes, not a gauge. Use the soil and the timing too.
• Raccoon and skunk cones look alike. Clemson gives them one description. The rolled sod points to a raccoon. Otherwise the tracks decide.
• Ranges. UGA describes the armadillo's range in the South as rapidly expanding over the past 50 years; Clemson notes them as far north as Anderson and York counties in South Carolina. Outside that range, shallow pits are skunks or raccoons. Rooted turf on a large scale is feral hogs.
• Law. We give Georgia, Florida and South Carolina only. Check your state wildlife agency before trapping anything.

Every other symptom in the yard is matched to its cause on the problems hub.

Frequently asked questions#

What makes small round holes under a bird feeder?

If the hole is about 2 inches across with no soil piled around it, it is one of four animals. A shallow dead-end pit is a gray squirrel burying or digging up food. A deeper hole beside a stump, step or woodpile is a chipmunk, which carries its soil away in its cheek pouches. Several openings joined by 1 to 2 inch runways through clipped grass are voles. A 2 to 3 inch hole worn smooth near shrubs, with droppings nearby, is a rat. All four are there for the seed on the ground.

What is digging holes in my yard at night under the bird feeder?

Cone-shaped holes 3 to 4 inches across that were not there at dusk are a skunk or a raccoon. Both dig for beetle grubs and other insects, and Clemson Extension says the damage happens at night. In the Southeast, many shallow pits 1 to 3 inches deep with uprooted plants are an armadillo, which forages from sunset into the early morning in summer. Rats also dig after dark but leave one or two burrows, not a scatter of pits.

Do armadillos eat bird seed?

None of the sources we read lists seed in an armadillo's diet. UGA Extension puts the diet at often more than 90 percent insects, grubs and earthworms, and UF/IFAS at about 75 percent insects by volume, mostly beetles, with the rest mainly other invertebrates. An armadillo digging under a feeder is digging for grubs in moist soil. Raking up seed will not stop it, and there are no registered repellents or toxicants for armadillos.

Should I put grub killer down to stop the digging?

Only if grubs are the reason, and only for the grub diggers. Skunks, raccoons, armadillos and moles hunt soil insects, so fewer grubs means less digging. Clemson Extension says the most efficient time to treat is early July, when grubs are small and close to the surface. It does nothing for chipmunks, voles, rats or squirrels, which dig for seed and shelter. ICWDM adds that skunk digging usually stops on its own after about 3 weeks, once the grubs in that patch are eaten.

Sources and further reading

1. Holes in the Lawn, HGIC 2364 (revised 13 December 2014) Chuck Burgess, revised by Joey Williamson, Clemson Cooperative Extension Home and Garden Information Center Bird poke holes with no soil; nickel-size insect emergence holes; vole entrances 1 to 1.5 in, no mound; squirrel holes 2 in, shallow, no mound; chipmunk 2 in, no soil; groundhog 10 to 12 in with mound, daylight; skunk and raccoon cones 3 to 4 in, area to 10 in, at night; rat to 3 in; armadillo 1 to 3 in deep, 3 to 5 in wide, sunset to early morning, burrow 7 to 8 in; grub treatment early July; SC DNR no relocation
2. Evaluating Attractants for Live-Trapping Nine-Banded Armadillos, Circular 889-3 (minor revisions 26 August 2024) Gammons, Mengak and Conner, University of Georgia Cooperative Extension Shallow holes 1 to 3 in deep and 3 to 5 in long; diet often more than 90 percent insects, grubs and earthworms; not protected in Georgia, may be hunted or trapped year-round without limit; 10 captures in 1,332 trap nights, baits no better than unbaited traps
3. Baiting the Nine-Banded Armadillo, WEC317/UW362 Ober, DeGroote and Mizell, University of Florida IFAS Extension Dozens of shallow holes 2 to 6 cm wide and up to 15 cm deep each night; prefers moist soil in well-kept lawns; about 75 percent of diet by volume insects, mostly beetles; invasive in Florida; no registered repellents, toxicants or fumigants; short perceptual distance
4. What's Digging Holes in the Lawn? (26 October 2022) Ashley Bodkins, University of Maryland Extension, Maryland Grows Skunk foraging for grubs and insects in early morning; attractants include bird seed and feeders, pet food, trash and compost
5. Armadillos: damage identification and biology Internet Center for Wildlife Damage Management (ICWDM) Holes 1 to 3 in deep and 3 to 5 in wide; biology page: burrows 7 or 8 in, up to 15 ft; summer activity twilight to early morning, winter in the warmest part of the day; more than 90 percent of diet insects, especially larvae; leprosy
6. Skunks: damage identification and biology Internet Center for Wildlife Damage Management (ICWDM) 3 to 4 in cone-shaped holes dug for grubs; section-by-section digging; damage generally stops after 3 weeks; raccoons and dogs also dig lawns; skunks nocturnal, den in old woodchuck holes and under decks
7. Chipmunk biology Internet Center for Wildlife Damage Management (ICWDM) Burrow entrance about 2 in, no mound because soil is carried off in cheek pouches; main tunnel 20 to 30 ft; caches food year-round; defends about 50 ft around the entrance
8. Norway rats and vole damage identification Internet Center for Wildlife Damage Management (ICWDM) Rat holes 2 to 3 in, clean of debris, hairs at the entrance; burrows by walls, fences, bushes and debris; flour tracking patch. Vole page: runways 1 to 2 in with openings to burrows, clipped vegetation
9. Woodchucks (Penn State Extension) and woodchuck identification (ICWDM) Penn State Extension; ICWDM Main entrance 10 to 12 in with a large mound of excavated earth; secondary entrances dug from below have no mound
10. Voles (Meadow Mice), Pest Notes 7439 University of California Statewide IPM Program Runways lead to multiple burrow openings about 1.5 to 2 in across
11. Tree squirrel biology and damage identification Internet Center for Wildlife Damage Management (ICWDM) Gray and fox squirrels scatter-cache seeds and nuts around their home range; squirrels damage lawns by burying or digging up nuts