Out in the woods, digging animals are an essential part of the ecosystem.
They aerate the soil, create important habitats for other creatures, and control insects and other pests.
In urban and residential areas, though, animals that burrow under concrete can wreak havoc on homes and structures.
If you’re wondering, “what is digging holes around my foundation?” you’re not alone.
At Smith’s Pest Management, we help resolve the issues caused by animals burrowing concrete daily in the San Francisco Bay Area, so we know what it takes to get these critters under control and prevent further property damage.
In this blog, we’ll share our top tips for identifying and stopping animals that burrow under concrete.
- Moles, voles, ground squirrels, gophers, and skunks burrow under concrete structures.
- Left untreated, these burrowing pests can quickly cause dangerous, expensive damage to your foundation, slab, sidewalk, or driveway.
- Controlling burrowing pests requires a comprehensive approach tailored to the pests on your property. Common tactics include exclusion, trapping, baiting, habitat modification, and repellents.
- If DIY efforts fail, we recommend contacting a professional pest management company that can get pest populations under control quickly and prevent further damage to your concrete structures.
Why Do Animals Burrow Under Concrete?
If you’ve noticed burrowing pests digging under the concrete around your home, they may be drawn to the following things:
1. Shelter and Safety
All animals need safety and shelter, and the space beneath concrete makes an excellent habitat.
Concrete is durable, water-resistant, and strong, and it protects anything living beneath it.
When we see pests digging holes around a building’s foundation, we can safely assume that they’re looking for a warm, dry place to call home.
2. Food Sources
Lots of digging pests eat insects and grubs as their primary food source.
To find these food sources, they need to dig through the soil. Sometimes, this may lead them to dig under your sidewalk, foundation, or concrete slab.
Animals like ground squirrels, moles, and voles all build tunnels, burrows, or nests.
Because concrete offers such excellent shelter, many of these pests build nests under or near a concrete foundation or slab, which protects them from predators and the elements.
How do Burrowing Animals Damage Concrete Foundations?
Burrowing animals can cause significant damage to concrete foundations and structures.
Here are a few of the biggest dangers associated with burrowing pests:
- Concrete collapse. Compacted soil is the stable surface necessary for any concrete structure. Unfortunately, burrowing pests excavate the soil beneath the concrete, destroying the compacted base and compromising the strength and tension of the concrete. As a result, concrete cracks and will eventually collapse.
- Sinking or failing concrete. As they dig, rodents create soil erosion and drainage issues, which can cause concrete slabs to settle, shift, or crack. When this happens, you must tear the affected concrete out and replace it, which can easily cost thousands of dollars.
- Holes in crumbling concrete. If your concrete structures are old, there’s a chance rodents can damage them by chewing through the concrete material. While new concrete that’s properly sealed, poured, and mixed is impervious to rodent teeth, older concrete slabs that are deteriorating or crumbling can expose the less dense innards of the slab, which could be susceptible to gnaw damage by rodents.
What are The Signs that Animals Are Burrowing Under Your Concrete?
Need help determining if you have animals burrowing under your concrete? Look for these signs:
- Digging under your deck or porch. If your home has a deck or porch attached, look for signs of digging under this structure. This may be the rodents’ “first stop” before they move on to digging under your slab or foundation.
- Mounds or holes. The most obvious sign that rodents are burrowing under your concrete is new mounds, holes, or tunnels near your foundation, walkway, or slab. Depending on the type of animal doing the damage, these holes may or may not feature soil mounding at the entrance.
- Cracks, sinking or shifting. If your concrete is sagging, sinking, cracking, or shifting, it could signify that rodents are burrowing beneath it and causing soil erosion and instability. This is especially true under or around new slabs, paths, or walkways.
- Water runoff issues. If you’ve noticed water pooling in strange places or draining in new patterns, it could be the product of unseen rodent damage. Rodents can divert water runoff pathways as they dig, causing dampness or pooling near your structures.
- Rodent sightings. If you’ve recently seen ground squirrels, moles, gophers, or other animals on your property, you’ve got good reason to worry about them digging under your foundation. Because concrete offers excellent protection and shelter, it’s one of the first things rodents will dig under when they infest an area.
5 Types of Animals that Burrow Under Concrete
Need help determining what kind of animal is burrowing under your concrete?
These are the most common culprits:
1. Ground squirrels
For residents of the Western United States, ground squirrels are the rodents most likely to dig holes under your concrete.
The California Ground Squirrel, specifically, (Spermophilus beecheyi) lives throughout the West and is known for being an active, prolific digger.
These ground squirrels breed and multiply quickly and can create extensive, interconnected burrow systems that plunge beneath concrete slabs and foundations, causing dangerous soil shifting and instability.
To identify ground squirrel damage, look for mounded burrows with piles of soil and rock at the entrance. They construct burrows that are about 4-5” in diameter, 2.5-4’ underground, and 5-35 feet long.
You may also notice crop or lawn damage in the vicinity.
Moles (scientific name Talpidae) are excellent diggers, and they’re known for digging tunnels under concrete. There are a few reasons moles do this.
First, the warmth emanating from a home into the soil around it lures in bugs, grubs, and other insects moles love to eat.
Secondly, concrete foundations and slabs provide shelter from ice, rain, and the elements and prevent predators from digging straight down into mole tunnels.
To identify mole damage, look for holes marked by mounded piles of soil. Moles also create tunnels and trenches in the top layer of soil as they dig.
Don’t let their tiny size fool you – voles (scientific name Microtus californicus) are skilled diggers that create elaborate networks of tunnels in lawns, gardens, and – sometimes – under concrete.
If voles are present, they’ll leave 1-2” paths on your turf and burrows that look like holes around your concrete foundations, slabs, and walkways.
Unlike moles, voles don’t create mounds of soil as they excavate their tunnels.
Gophers (scientific name Geomyidae) love to tunnel under foundations, slabs, and concrete walkways to create food storage and living spaces that are protected from predators and the elements.
You can identify gopher damage under your foundation by looking for large tunnels (much larger than what a tiny vole would create) that don’t have mounded soil at the entrance.
Areas with large gopher infestations may feature dozens of entrance and exit holes that vary in size.
Skunks (scientific name Mephitis mephitis) aren’t as skilled at digging as gophers, voles, ground squirrels, or moles.
If and when they dig around concrete, they’ll dig shallow holes under foundations or slabs, mostly in search of food.
Skunks digging deeper burrows will displace a lot of soil in the process, which could cause severe problems for your concrete structures. These deeper holes are usually used for raising young and sleeping.
To identify skunk damage, look for a combination of large and small tunnels in your yard and around your concrete structures.
You’ll also be able to verify the presence of skunks by the telltale smell they leave behind.
The Best Prevention and Control Methods for Burrowing Pests
Fixing concrete damage caused by rodents can cost thousands of dollars.
Fortunately, you can usually save your concrete structures by identifying and controlling rodent infestations as quickly as possible.
Here are our top tips:
Controlling ground squirrels requires a combination of management tactics, including cultural and biological control. Here’s what we recommend:
- Fumigants. Fumigants are a top go-to for ground squirrel control. Since fumigation is conducted underground, it’s also a great way to deal with ground squirrels that are burrowing beneath concrete structures. For fumigation to be most effective, it should be conducted in the spring when the soil moisture levels are high.
- Baiting. Baiting with first-generation anticoagulant formulas is a great way to eliminate ground squirrel populations and protect your concrete structures. When ground squirrels consume first-generation anticoagulants, they go underground and die in their dens. This prevents hawks, owls, and other predators that like to eat ground squirrels from secondary poisoning. We recommend baiting as a control method for large populations of ground squirrels. For the treatment to be most effective, it should be completed during the summer or fall.
- Trapping. Trapping is a practical, efficient way to get rid of ground squirrels. Here at Smith’s Pest Management, we recommend using live ground squirrel traps, which contain the squirrels humanely and allow you to control populations quickly.
- Habitat modification. In addition to fumigation, baiting, and trapping, we recommend habitat modification as a control method. To deter ground squirrels, remove clutter near your concrete structure, trim bushes and shrubs to remove hiding places, and eliminate all food sources.
- Repellents. Make the area inhospitable for ground squirrels by using natural repellents like homemade pepper spray or castor oil near burrows and tunnels. You can also purchase green and eco-friendly repellents at home improvement stores.
- Exclusion methods. Reinforce affected areas by adding patio blocks or trench screening, which will prevent animals from digging new burrows in the future.
For more information on how to get rid of ground squirrels, check out our complete ground squirrel elimination guide.
To get rid of moles, you’ll want to use effective, comprehensive control tactics, including habitat modification and exclusion.
Here’s what we recommend:
- Have your yard treated for grubs. Grubs are a mole’s primary food source. By eliminating the grubs and other tasty insects in your yard, you’ll naturally make the area less attractive for moles. In addition to investing in a professional grub treatment, you can use natural control agents like beneficial nematodes or milky spore to eliminate grubs.
- Repellents. Mole repellent can be an effective way to deter moles from digging around your concrete structures. For example, a mixture of three parts castor oil and one part dish soap will cause digestive upset for the moles who encounter it. Alternatively, you can purchase pre-made mole repellent at your local hardware or home improvement store.
- Exclusion methods. One great way to protect your concrete structures from moles is to dig a trench about 2’ deep and 6” wide, bordering the area you’d like to protect. Line the trench with hardware cloth or wire mesh to keep animals from digging under your foundation.
- Habitat modification. To deter moles, modify the habit to remove shelter. Get rid of clutter, trim bushes and shrubs, and keep your grass mowed. You can also create an artificial drought by watering your lawn and gardens less frequently.
- Trapping. To control large mole populations, place traps directly inside active mole runways. For humane removal, we recommend using live traps to get rid of moles without killing them.
For more information about how to control mole populations, check out our complete mole removal guide.
To eliminate voles and protect your concrete structures, you need to think like a vole. You can control populations quickly and efficiently by removing their food sources and shelter and making their habitat unpleasant.
Here are a few control methods we recommend:
- Habitat modification. Voles are tiny prey animals, and they try not to feed out in the open. To make your property less appealing, remove dense ground cover, fill existing holes, trim your grass, and use light mulch around your trees and shrubs. Remove clutter and food sources, and keep bushes and shrubs trimmed.
- Traps. Live traps capture voles without killing them. For best results, we recommend positioning live traps in front of vole holes and using oatmeal or peanut butter to bait them. If you have a severe vole infestation, you may need to use humane, lethal traps to control voles quickly before they can reproduce.
- Repellents. Natural and store-bought repellents can control vole populations. Natural repellents like castor oil and capsaicin work well, as do store-bought vole repellents available at home improvement centers.
- Exclusion methods. To prevent voles from digging near your foundations, driveways, sidewalks, or concrete slabs, dig a trench and line it with hardware cloth. This prevents voles from tunneling or digging through the material and making it beneath your concrete structures.
For more information about how to get rid of voles on your property, check out our complete guide.
Gophers are some of California’s most common (and persistent) pests. To get rid of them near your concrete structures, use these control methods:
- Habitat modification. Gophers need shelter to live, breed, and thrive. To deter them, keep your yard and garden clean and tidy. Get rid of weeds, plant gopher-repellent varieties like catmint and lavender, and remove clutter from your yard.
- Exclusion methods. Use gopher wire to create a barrier around structures you’d like to protect. For best results, we recommend digging trenches and lining them with gopher wire with openings less than ½” x 1”.
- Repellents. Repellents are an excellent, natural way to deter gophers. Homemade repellents like castor oil, tabasco, and peppermint oil will make your property unpleasant for gophers. You can also purchase pre-made, eco-friendly gopher repellents at your local hardware or home improvement store.
- Trapping. Live traps are an excellent way to get rid of gophers. For best results, set traps in active gopher tunnels, and bait them with food gophers love, like peanut butter, lettuce, or apples. Move any trap that has not captured a gopher within 48 hours to a new location.
- Baits. Gopher baits can be an effective control method, but they must be used carefully. In California, rodenticide laws state that baits must be placed underground rather than at lawn level. This reduces the risk of secondary poisoning in predators that eat gophers.
For more information on how to control gophers effectively, check out our complete gopher management guide.
To get rid of skunks, you’ll want to focus on the following three control methods:
- Trapping. Humane, live traps can catch skunks and enable their relocation. Because skunks are intelligent, mostly nocturnal creatures, you may want to enlist the help of a professional pest management company, like Smith’s, to trap the pests efficiently.
- Habitat modification. Most skunks are drawn to a property because it provides ample food. By removing food sources through professional grub and insect treatments, you can reduce skunk populations and prevent them from burrowing under your concrete structures to store their food.
- Exclusion. Effective skunk exclusion efforts focus on sealing entry points that allow skunks access to concrete structures, installing lined trenches and exclusion fencing, and using repellents to make the area inhospitable for these pests.
To learn more about how to get rid of skunks on your property, check out our skunk control guide.
Are Animals Destroying Your Concrete in the San Francisco Bay Area? We Can Help!
Your home is an investment, and your concrete structures are critical to your property’s look, feel, functionality, and safety.
While burrowing pests can quickly cause thousands of dollars of damage to concrete patios, driveways, sidewalks, foundations, and slabs, the good news is that you don’t have to stand by and watch it happen.
If you’re in the Bay Area, Smith’s Pest Management is here to help.
We provide comprehensive burrowing pest removal services for clients along the Central Coast and throughout the Bay Area daily. We know how to exclude, control, and remove pests like ground squirrels, gophers, moles, voles, and skunks.
Ready to take a stand and protect your concrete structures? Request your free pest control quote now!