Lizard Holes In Your Yard: A Comprehensive Guide

If you have found small holes appearing mysteriously in your yard, there’s a good chance lizards are responsible. Getting to the root of these reptilian excavations can help you understand why they are happening and what to do about them.

If you’re short on time, here’s a quick answer: Lizard holes in your yard are typically a sign of native lizards burrowing underground to find food, water, shelter, and safe places to lay eggs. Filling in the holes rarely solves the problem long-term.

Your best bet is to make your yard less attractive to lizards by clearing dense vegetation, limiting hiding spots, and keeping the area dry.

In this comprehensive guide, we will explore common reasons for lizard tunneling, signs to look for, pro tips for preventing holes from returning, and whether it makes sense to fill in lizard burrows or leave them be.

Common Causes of Lizard Burrowing

Shelter from Predators and the Elements

Lizards dig holes and burrows to create shelters that protect them from predators and harsh weather conditions (The Spruce). Underground burrows maintain more stable temperatures than the surface, allowing lizards to stay warm or cool as needed.

Burrows also provide safety from hungry birds, mammals, and other reptiles looking for a lizard snack.

Access to Food Sources

Some lizards burrow to be closer to their main food sources. For example, horned lizards dig tunnels to reach harvester ant colonies, their primary prey. Accessing ant burrows underground allows the reptiles to ambush the insects as they exit and enter the colonies.

Certain skink species also burrow to eat grubs, beetles, and other insects living in the soil (Washington Department of Fish and Wildlife).

Safe Nesting Sites for Eggs

Female lizards need secure nesting locations to lay their eggs, away from predators that might eat the vulnerable clutches. Many lizards dig burrows or hide their eggs under rocks, logs, or leaf litter on the ground.

For example, the six-lined racerunner lays eggs about one inch underground, while fence lizards conceal eggs under soil, debris, or thick grass (Savannah River Ecology Laboratory). Once the young hatch, they may continue living in the abandoned burrow for safety.

Overwintering Shelter

In cold climates, lizards need protected spots to brumate through the winter months when prey is scarce. Species like the northern fence lizard dig hibernacula burrows below the frost line to avoid freezing temperatures. These underground shelters have high humidity levels needed for brumation.

Lizards generally emerge the following spring when temperatures warm and food becomes available again (Penn State Extension).

As the examples above show, different lizard species burrow for overlapping reasons, with finding food, laying eggs safely, and having year-round shelter being common motivations. Understanding why local lizards dig tunnels can help homeowners coexist with these small reptiles rather than viewing them as pests.

Identifying Lizard Holes

Small, Round Entrance Holes

One of the key signs of a lizard hole is a small, circular opening in the ground, averaging 1-3 inches across. These entrance holes lead to an underground burrow or nesting area excavated by the lizard.

The perfectly round shape allows the reptile to easily enter and exit while preventing larger predators from gaining access.

Often Appear Under Objects or Dense Vegetation

You’ll frequently discover lizard burrows situated under rocks, boards, thick bushes, or other concealed spots in the yard. These semi-protected areas help provide shelter and shade that lizards desire for temperature regulation and avoiding detection.

Check under debris piles, wood piles, boulders and dense flowering plants. Their preference for hiding spots allows lizards to safely nest and raise young away from harm’s way.

May Have Mounded Dirt Around the Entrance

As lizards continuously dig out and refurbish their subterranean quarters, they will push excavated soil up around the opening. Look for small mounds of lightly packed dirt ringing these holes as a clue that they lead down to an occupied lizard den.

The excavated piles are often asymmetrical and appear hastily assembled. A neatly landscaped ring of soil likely indicates a different type of burrow like that of a gopher or ground squirrel.

Multiple Holes in Close Proximity

Due to their cold-blooded nature, lizards frequently shuttle between sunny basking spots and shaded refuge to stabilize their body temperature. You may notice several connected holes within a few square feet of each other, creating an extensive underground network.

These adjoining burrows allow quick escapes from predators and convenient movement between rest, warming, and nesting chambers as needed. A lizard hotel with multiple “rooms” offers safe, adjustable comfort mere steps away.

When inspecting any small burrow openings discovered in the yard, consider hole size, placement, excavated dirt piles and proximity to other holes to determine if a lizard may reside inside.

For more information, visit the California Herps Lizard Burrows guide.

Preventing Lizard Holes from Returning

Once you have evicted the lizards from your yard by filling in their burrows, you’ll want to take steps to prevent new unwanted tenants from moving back in. Lizards are attracted to certain environments that provide good hiding spots, protection, and accessible food.

Making your yard less hospitable can go a long way toward keeping lizards from returning.

Clear Dense Groundcover and Brush

Lizards love areas with thick groundcover plants, brush piles, wood piles, and other dense foliage. These areas allow lizards to stay hidden from predators while also having easy access to insects and other prey. Reducing this protective vegetation removes their natural habitat.

• Cut back overgrown plants, thick shrubs, and dense groundcover foliage. Areas around foundations and fences tend to become overgrown quickly.
• Rake up leaves, straw, mulch, and yard debris that’s accumulated under plants or in corners.
• Keep your lawn mowed short, as longer grass provides good cover.

Remove Wood and Rock Piles

Stacks of firewood, construction materials, landscaping timbers, and accumulated rocks provide the perfect hideout for lizards. By clearing these away, you leave them more exposed and vulnerable to predators.

• Disassemble unused wood piles; use or dispose of the wood properly.
• Consolidate essential rock piles away from the house foundation.
• Store construction materials neatly off the ground until needed.

Keep the Area Dry

Lizards lay their eggs in moist soil and need sufficient moisture to survive. Making your yard drier makes it less welcoming.

• Improve drainage of soggy areas using gravel, French drains, regrading, or plants that tolerate dry soil.
• Water lawn and gardens judiciously, allowing soil to dry out between waterings.
• Sprinkle diatomaceous earth on soil to absorb moisture; reapply after rain.

Limit Hiding Spots Near Foundations

It’s inevitable that small gaps and holes will develop over time along the foundation and sidewalks. Vigilantly sealing these makes it harder for lizards to sneak back inside.

• Inspect exterior walls, patio slab connections, vents, utilities, and foundations for gaps. Fill small holes with copper scrub pads or steel wool.
• Caulk, cement, or fill larger gaps. Expanding spray foam works well.
• Keep baseboards attached securely to walls with no gaps.
• Install Door sweeps and weatherstripping to seal the threshold gap.

Use Gravel or Rock Mulch in Problematic Areas

Gravel and crushed stone mulches provide a fairly inhospitable environment for lizards to traverse or dig in. Sprinkling these decorative mulches around areas that tend to have recurring lizard problems can help deter them.

• Apply 2-3 inches of gravel along the foundation and under decks or sheds.
• Use gravel or rock mulch beneath problem shrubs and trees.
• Refresh gravel mulches once a year as needed.

With diligence and patience in applying these preventive measures, you can successfully keep lizards from turning your yard into their homestead again. It may take time to evict current lizard residents and modify their accommodating habitat, but the results will be worth it.

Before you know it, your yard will be lizard-free and you can enjoy your outdoor spaces again without worrying about miniature dinosaur descendants!

Should You Fill In Lizard Holes?

Filling Holes is Often Temporary

Filling in lizard burrows and holes in your yard is usually a temporary solution at best. Persistent lizards will often just dig the holes again in a matter of days or weeks. According to the Washington Department of Fish and Wildlife, filling holes with dirt or rocks simply prompts lizards to reopen tunnels and remake chambers.

Can Disturb Nesting Lizards

It’s important to consider that filling in burrows could unknowingly cause harm to lizards nesting or sheltering inside. The Humane Society cautions that there may be eggs and baby lizards inside burrows that could be crushed or buried.

Instead, they recommend marking holes and monitoring for activity before taking action.

Holes May be Part of a Larger Burrow System

What appears to be a single lizard hole in your yard could actually be an entry point into an extensive underground burrow system. According to the California Herpetology Association, some burrows extend deeper than 3 feet underground and have multiple access points and tunnels.

Filling one hole may temporarily close access, but lizards will likely reopen or create new entry points nearby.

Consider Leaving Natural Burrows Intact

Natural lizard burrows play an important ecological role. They provide shelter for lizards and invertebrates and allow airflow between the surface and deeper soil layers. The Washington Department of Fish and Wildlife recommends leaving burrows intact whenever possible, as they rarely pose issues and are beneficial parts of a healthy yard ecosystem.

When to Be Concerned About Lizard Holes

Large, Deep Holes That Pose Safety Risks

Lizard holes that are exceptionally large or deep can pose safety risks, especially in yards where children or pets play. Holes wider than 3 inches across and deeper than 6 inches warrant caution, as small hands, feet or paws could become stuck.

Additionally, a twisted ankle is possible if accidentally stepping into an obscured lizard hole.

Check for lizard holes near play areas, under swings, slides, jungle gyms, etc. Fill these in with dirt and monitor them to ensure lizards don’t reopen them. Placing play equipment on top of rubber mulch or wood chips instead of dirt can also deter lizards from digging in high traffic zones.

Holes Near Foundation Cracks or Settling

Numerous or expanding lizard holes found near your home’s foundation or in areas with visible soil erosion merit attention. Their burrowing can worsen foundation issues and lead to further subsidence or collapse.

Inspect the foundation and surrounding soil for cracks, sinking, or other abnormalities, especially after heavy rains.

Consult a structural engineer if you suspect lizard tunnels are compromising the integrity of your foundation. Stabilization, drainage adjustments or foundation repairs may be needed. Severe undermining can even necessitate pest control measures to remove lizards and fill tunnels before they expands any further.

Rapid Reappearance After Filling In Holes

It’s normal for lizards to eventually reopen filled tunnels. But if fresh holes rapidly appear daily or weekly in the same spots, it indicates prime burrowing conditions in that location. Frequent tunneling causes soil loosening and erosion over time.

Improving soil compaction, adding sand or gravel, or laying pavers or stones can deter redigging. Altering the drainage or moisture conditions impacting their preferred nesting sites can also convince lizards to move elsewhere.

Persistent re-burrowing likely means additional deterrence methods are needed.

Seeing Multiple Lizards Near Holes

Lizards are solitary creatures, so seeing more than one close together often means a prime nesting habitat exists. Numerous holes accompanied by regular lizard sightings signify an infestation could be forming.

Monitor for increased digging, burrowing and lizard traffic. Keep vegetation trimmed back and remove wood or rock piles providing shelters. Although some elusive lizards are normal, large concentrations may warrant professional pest control or humane relocation if problems persists.

Stay proactive before colonies become established.

Conclusion

Lizard holes in your yard are rarely cause for alarm and are often a sign of a healthy local ecosystem. With some diligent landscaping modifications to make your yard less hospitable, you can minimize new burrowing activities over time.

Understanding why lizards dig in the first place can help inform your approach. In most cases, filling in holes provides only a temporary fix. As tempting as it may be, allow natural lizard burrows to remain undisturbed whenever possible.

With the proper context and preventative measures, you and your new scaly yardmates can find ways to happily coexist.