Animals That Burrow Under Concrete
Animals that burrow under concrete
Concrete is exceptionally strong, making it an ideal material for foundations, but even it will deteriorate given enough time. When it comes to concrete damage, common culprits include improper installation or poor soil conditions, freeze / thaw cycles and improper water drainage. In some cases, burrowing animals are to blame—and they can wreak havoc on your concrete in a number of ways.
Rats, mice, moles, voles, gophers, and several other types of ground-burrowing rodents are natural diggers, constantly seeking out shelter and sources of food. Sometimes, they choose to make their dwelling space underneath concrete foundations. This leads to a multitude of problems that can become serious issues and may lead to structural failure if not addressed promptly.
ground squirrels and other animals could be digging in your yard and under your sidewalks, patio, stairs, steps, or driveway. This animal infestation can create voids and cause the slab to settle and crack. Examples of animals that burrow include rabbits, ants, otters, chipmunks (ground squirrels), foxes, moles, and shrews.
These are some signs of animal activity.
What Animal Can Dig Through Concrete?
If pests are chewing holes in concrete patios, foundations, pathways or driveways at your house, it is likely the concrete is weak. It’s also likely you have rats (Rattus spp.) because no other insect or animal pest is known to chew through concrete. Although they can’t chew holes in solid concrete, they can chew through if it’s weak or loose. If you think you may have rats, they’ll leave signs you can look for to be sure.
Rats are nocturnal, so you likely won’t see them. Instead you’ll see signs they were there. Check for droppings near pet food or garbage cans. Listen for attic noises after dark, like scratching or running. Check around the foundation for small trails with bare ground or look for digging around plants. If you find signs of rats, block holes around the house with metal sheeting. Set traps to catch the rats in areas you see droppings or chew marks, as well as in dark corners or ledges. If you have pets that may get into the trap, set it in a box, leaving one end open.
Repairing Damaged Caused By Animals That Burrow Under Concrete
When it comes to concrete damage caused by rodents, your best course of action is to contact a concrete raising company for mudjacking services. While certain concrete projects such as resealing or leveling with a compound are DIY-friendly, raising a concrete slab as a result of underlying voids is a more complex and demanding process that merits professional experience, skills and equipment.
The mudjacking process is simple: first, holes are drilled into the affected slab to allow for insertion of the slurry mixture. The slurry (a mix of cement, water, and dirt) is then pumped through the holes and under the slab to fill the void and raise the concrete to the proper level, after which the holes are filled and sealed.
Mudjacking is an effective long-term solution for sinking concrete, but it’s not a cure-all. Severely damaged concrete may be beyond repair, and should be replaced altogether.
Contact pest control: Each type of critter needs to be handled in different ways. If you have questions about the type of animal digging up your yard it is best to get advice from a professional. Otherwise, you will just continue to have the problem year to year.
Contact a concrete specialist in your area: Our network of foundation repair companies also includes a large number of concrete experts. They can use tools such as ground-penetrating radar to detect voids. Earth Contact Products has a product called PolyPier that many of our contractors utilize for raising and leveling concrete slabs. Polyurethane is injected beneath the slab and pumped into the void to fill the void and raise the concrete back to the correct position. PolyPier uses NCFI polyurethanes that are tested and proven to provide a permanent solution for void filling and concrete repair.
Prevention Of Damages Caused By Animals That Burrow Under Concrete: Mostly Rodents
Once your sinking concrete issue has been resolved, the last thing you’ll want to do is turn a blind eye and forget about it. Burrowing rodents, if unchecked, could return to the same area and wreak havoc all over again. Make sure to keep an eye on the area for as long as necessary to ensure no furry critters continue to call it home.
If you happen to catch rodents underneath your concrete early enough, it’s possible to rectify the situation before any lasting damage is done. This can be accomplished through rat poison and smoke or gas bombs which are easily found at home improvement stores and online. Always make sure to read all safety info and documentation for these products before using them.
As a last resort, if rodents have completely overtaken an area of your property beyond your control, consider hiring a pest control specialist to eradicate the infestation once and for all.
While not the most common cause of sinking or damaged concrete, the possibility of burrowing rodents causing concrete damage remains very real for virtually any structure.
If you or someone you know has fallen victim to damaged concrete due to rodents, complete a form and obtain several quotes.
- Fill existing holes. This is the first step to keeping animals out. Any holes around your home’s foundation should be refilled with soil and tamped down so it is solid and not loose.
- Treat the area to deter animals. There are chemical products on the market that make wild animals avoid areas due to their strange or offensive scent. Do some research into these products to determine if they will resolve your problem. Those with pets may wish to avoid, as they can affect friendly animals as well as unfriendly ones.
- Remove shrubbery and landscaping obscuring burrows. Removing all greenery from your yard is unnecessary, but you might want to trim back bushes that cover the area where your foundation connects to the earth. This prevents animals from avoiding your notice, and helps you spot additional problem areas more easily.
- Reinforce the area. Adding cement, patio blocks or trench screening to the area, after it’s been completely cleared of wildlife, will help ensure that nothing digs into it again. Landscaping to prevent animal digging doesn’t have to look ugly, and can prevent huge repair costs if done in a timely manner.
Eliminate Sources Of Food
Most animals seek shelter near or in a home because there’s an available food source: a garden, pet food, bird food, or garbage in garbage cans. No matter how cute or helpless these animals look when they’re peeking out from under your deck, “you absolutely, positively should not feed them!” the WHS says.
- Protect your garden with a fence. “A chicken-wire fence will work nicely,” says Kwochka. “It needs to be at least 3.5 feet high and buried 1 foot into the ground with the fence angled away from the garden.”
- Use garbage cans with lids that seal tightly. Weigh down the lids with bricks or other heavy objects, if needed, to keep animals from getting under them.
- Feed the birds, not the forest. Use a bird feeder with a seed catcher tray, and sweep up up seeds and hulls frequently.
- Keep pet food indoors. Don’t feed your pets in the garage or on the deck. Bring the food bowl inside after giving your pet a reasonable amount of time to eat. Don’t leave food out overnight.
Usage Of Tracking Powder
I decided to use a tracking powder, a dust that adheres to the rodent’s fur and paws. Then when the animal grooms itself, it ingests a lethal dose. With tracking powders, it is important to keep non-target animals like dogs and cats away from those areas where the treatment is applied or where they could potentially find poisoned pests. In this case, I applied the powder directly into the burrow hole and then covered it to prevent non-target animals from reaching the powder. I told the homeowner to contact me if he saw any new burrowing activity. However, I’m not expecting a call anytime soon. Once this tracking powder sticks to the animal, it’s game over. Whatever burrowing creature is digging around the home — whether vole, mole, or shrew — it won’t be digging around much longer.
Rodents That Burrow Under Concrete: How They Produce Damage
By Burrowing Under It
Soil settlement and shifting is one of the most common problems associated with sinking or failing concrete. There are several factors that contribute to shifting soil, such as erosion and drainage issues. Although less common, burrowing rodents can also lead to soil displacement, and often at much faster rates than elemental factors.
Rodents will dig under anything and everything they can in search of a new home or to avoid predators. This includes burrowing under concrete slabs and foundations, leading to rapid creation and growth of voids that threaten the structural integrity of the slab and create danger hazards. What takes years for the elements to achieve as far as deterioration, a large family of mice or rats can accomplish in a few days.
When voids do form as a result of burrowing rodents, they can lead to cracked or sinking concrete. These types of voids are especially dangerous in that there is often no visual indication of their presence; a fully healthy-looking concrete slab may have a sizeable void underneath, creating severe danger for unsuspecting people above.
By Chewing Through It
Certain types of rodents are more akin to digging than others. Mole rats, for example, are equipped with giant front teeth and large claws meant for burrowing, while standard house mice are built for gripping and climbing. However, nearly all modern rodents have front incisors that grow continually and require constant gnawing to maintain, so it’s all but guaranteed that if a rat’s been around for a while, they’ve been chewing at something.
Of all the things a rodent could chew on, concrete ranks fairly low, but it’s certainly not unheard of. When properly mixed, poured and sealed, a rat’s teeth won’t stand a chance against concrete. However, a deteriorating or crumbling concrete slab can expose its less dense innards. Though far from comfortable chewing, these porous concrete “guts” are more susceptible to gnawing away by rodents, especially in times of desperation.
This is just one of many reasons why a crumbling concrete slab requires prompt action; it often points to and acts as a catalyst for more severe issues.
Signs Of Animal Activity
Here are some other signs of animal activity to look for that will help you narrow down the possible suspects.
- If you have noticed digging under your deck or porch, small patches of torn-up grass, and a distinct odor, it’s most likely a skunk. Skunks burrow under structures and often feed on grubs and insects.
- If there are noises in your attic, you probably have squirrels or raccoons nesting. Raccoons will come out at night; squirrels most often during the day. Young raccoons often sound like puppies and can be very vocal.
- If you have long underground burrows in your grass and your garden, and have noticed flowers are eaten, chances are a woodchuck − also known as a groundhog or whistle-pig − has made your lawn his home. Smaller burrows and disappearing flower bulbs may indicate chipmunks or moles.
Those chipmunks and groundhogs might be cute and entertaining, but they can do some serious damage. According to Nora Kwochka at Bobbex Deer and Animal Repellents, “An average groundhog excavates 700 pounds of dirt for one den. They may have four or five dens in their territory.”
Groundhog damage may not be limited to the yard. Groundhogs also burrow under houses, especially those that are built on slab foundation.
“Given the speed at which it digs and the amount of dirt it can excavate, the groundhog can do tremendous damage to the underside of a house by loosening the ground on which the structure is built,” according to Havahart pest control.
The Wisconsin Humane Society says that the species most encountered in basements in the Milwaukee County area are gray squirrels, eastern chipmunks, house sparrows and European starlings. “They may come in through the furnace system, dryer vent, a broken door or window, or a door or window that has been left open.”
Oddly enough, the best place to look for an animal entrance to the basement is up − at your chimney, the WHS says. Installing a chimney cap will keep critters out of your entire home. Or, look down at your dryer vent. A vent guard is easy to install, doesn’t cost much, and will stop smaller animals from crawling in.
The holes could be rat burrows, especially given their location, but keep in mind that other animals (such as meadow voles, moles, and deer mice) can also dig burrows in your yard. In buildings, brown rats (also called Norway rats) can nest almost anywhere – in wall or ceiling voids, in upholstered furniture, in attics or crawlspaces. But in their natural habitat outdoors, brown rats are burrowers.Rats especially like to burrow under rocks, concrete slabs, or other heavy objects. They are notorious for digging burrows under the concrete slabs that dumpsters sit on. Here they have a cozy home with ready access to food from the dumpster. They also burrow in thick ground vegetation like English ivy or under low, thick shrubbery.
The rat burrow itself rarely goes farther down in the ground than 18 inches but can be much deeper when rats are trying to dig under foundations. Burrows are usually less than 3 feet long with a central nest area filled with leaves, grass, or soft debris.The size of the burrow opening is often the key to whether you are dealing with rats or some other burrowing animal. The main opening to a brown rat’s burrow is 2 to 4 inches in diameter and is smooth from use. The opening will often have freshly excavated dirt strewn in a fan shape around the outside of the opening. To tell whether a rat burrow is still active, pest management pros often fill the burrow with debris or partially collapse it, then check back to see whether the rats have reopened the entrance. A rat burrow will have extra bolt, or escape, holes as well. These secondary holes may be hidden under objects or even lightly plugged with dirt.
If you live in the western U.S., the most likely rodent to dig holes under concrete is a California ground squirrel (Spermophilus beecheyi). They range from southern Washington to northern Mexico. Ground squirrels increase quickly and create large and extensive interconnecting burrow systems that can damage buildings and other structures or equipment. Once a sizeable ground squirrel population becomes entrenched, it takes work and perseverance to control them and then to prevent reinfestation.
California ground squirrels range in size from 14 to 20 inches long, including the tail, and weigh from 1/2 to 2 pounds. They are heavy-bodied, with long, bushy tails and speckled gray-brown fur. The undersides are lighter-colored and squirrels have a white eye-ring. Family groups tend to stay together in communal burrows, with numerous squirrels living together. A colony of squirrels can quickly undermine a piece of concrete with their burrows. They are excellent diggers, and forepaws are good at grasping and handling food.
Equipped with several exit and entrance holes, burrows are a work in progress. California ground squirrels constantly modify, interconnect and enlarge the burrow system they occupy. Entrance holes can be 4 inches wide but vary considerably. Their foraging area extends about 75 yards out in all directions from their burrows. Fencerows, borders of fields and around buildings and pavement are preferred burrow areas. The Food and Agriculture Organization of the United Nations considers ground squirrels as urban pests since they thrive in areas modified by human activities. They take advantage of constructed sheltering places, like building foundations, dams and woodpiles, and they benefit from irrigated plants, dripping faucets and pet and livestock feed.