To get rid of rats under a deck or shed, you must trap or bait the active rodent population, install physical exclusion barriers around the foundation, and eliminate nearby food and water sources. Combining population control with physical exclusion ensures rats cannot return once cleared. Addressing the infestation promptly protects your outdoor structures from undermining and structural damage.
Rats are naturally drawn to the quiet, covered space beneath decks, garden sheds, and outbuildings. These low-clearance areas offer ideal protection from predators and bad weather, making them primary nesting locations. Left unchecked, a burrow system beneath a slab or deck can undermine soil stability and lead to severe structural issues.
Signs of Rat Activity Beneath Decks and Sheds
Before beginning control measures, verify that rats are the source of the problem. Norway rats, the most common species to burrow under low outdoor structures, leave distinct signs of their presence around yard structures.
- Burrow Entrances: Look for smooth, circular holes approximately 2 to 4 inches in diameter near the edges of shed foundations or deck footings.
- Runways and Grease Marks: Dark, oily rub marks on deck posts, wood trim, or fence lines indicate frequent rodent travel routes.
- Fresh Droppings: Dark, capsule-shaped droppings around burrows or storage items confirm active infestations. You can confirm species by comparing mouse droppings vs rat droppings found near the site.
- Gnaw Marks: Freshly chewed wood on shed doors, floor joists, or plastic storage containers indicate active feeding or chewing.
Step 1: Remove Attractants and Shelter
Rats rarely settle in an area unless food and water are nearby. Removing these resources forces rodents to search elsewhere and makes baiting tactics significantly more effective.
Start by clearing fallen fruit, acorns, and nuts from surrounding yards. Secure household trash in heavy-duty cans with tight-fitting lids. Bird feeders are one of the primary drivers of outdoor rodent infestations; temporarily remove bird feeders or install seed catches to keep food off the ground. If you have pets, feed them indoors and remove outdoor water bowls overnight.
Next, reduce harborages around the perimeter. Stack firewood at least 18 inches off the ground and away from the shed or deck. Trim back low-hanging vegetation, dense shrubs, and tall weeds within three feet of the structure to eliminate protective cover.
Step 2: Trap and Remove the Existing Rats
Never seal off the underside of a deck or shed before trapping the existing population. Trapping rats inside forces them to chew new exit routes, potentially causing greater structural damage, or results in decaying carcasses that produce foul odors under your deck.
Place traps along active pathways, usually directly against the perimeter boards or near burrow entrances. Snap traps housed inside protective bait boxes work exceptionally well outdoors. When selecting traps, consider using durable, weather-resistant models designed for outdoor conditions, such as effective outdoor rat traps that withstand rain and dirt.
Bait traps with peanut butter, bacon grease, or nut butter. For difficult-to-catch rats, leave unset traps baited for a few days so the rodents become comfortable feeding around them before setting the triggers.
Safety Precautions for Traps, Chemicals, and Health
When implementing rodent control outdoors, protecting non-target wildlife, domestic pets, and children is paramount. Rodent control tools must be placed carefully to prevent accidental injury or poisoning.
If you opt to use rodenticide baits, always place them in tamper-resistant bait stations that lock securely. Always follow the manufacturer product label for application rates and safety guidelines. Explore safer options for outdoor rat control by prioritizing secured stations that keep children and pets safe.
Rodents carry pathogens that can spread through direct contact, urine, or droppings. Always wear rubber or nitrile gloves and a dust mask when handling traps or cleaning up burrow areas. Never sweep or vacuum dry droppings, as this aerosolizes particles; instead, spray the area with a disinfectant before wiping it clean. If a person or pet is bitten by a rat, wash the wound thoroughly with soap and water immediately and seek prompt medical attention or veterinary care. In cases where a pet ingests rodent bait, contact a veterinarian or animal poison control center right away.
Step 3: Install Physical Rodent Exclusion Barriers
Once trapping shows no signs of remaining rat activity, install an underground barrier to permanently keep rats from digging back under the structure. Simple surface coverings are ineffective against burrowing rats, which can easily dig beneath thin boards or shallow barriers.
The most effective method is installing an L-shaped curtain wall using half-inch or quarter-inch galvanized hardware cloth. This method prevents rats from burrowing under shed slabs or deck footings.
- Dig a Trench: Excavate a trench around the entire open perimeter of the deck or shed, roughly 12 inches deep and 12 inches wide.
- Attach the Wire Mesh: Secure the top edge of the hardware cloth to the wooden frame or base of the structure using heavy-duty staples or screws with washers.
- Form the L-Shape: Bend the bottom 12 inches of the hardware cloth outward at a 90-degree angle away from the structure, laying it flat along the bottom of the trench.
- Backfill: Fill the trench with soil or gravel and tamp it down firmly. When a rat attempts to burrow downward at the wall, it hits the horizontal mesh and gives up.
For additional details on sealing other vulnerabilities around your home foundation, consult step-by-step rodent exclusion techniques to seal openings effectively.
When to Call a Professional Exterminator
While DIY trapping and exclusion work well for minor infestations, extensive rodent burrow networks under large decks or concrete shed slabs can be challenging to eradicate. If burrows continue to reappear despite your efforts, or if you suspect rats have penetrated the interior wall cavities of adjacent structures, consult a licensed pest control professional. Professionals have access to specialized equipment and can safely execute complex exclusion strategies.
Frequently Asked Questions
Can I use expanding foam to stop rats under a shed?
Standard spray foam insulation is easily chewed through by rats and should not be used alone. If using foam to fill small gaps, combine it with stainless steel mesh, copper mesh, or hardware cloth to create a chew-resistant barrier.
How long does it take to eliminate rats under a deck?
Eradicating a typical outdoor rat colony usually takes between 1 to 3 weeks of continuous trapping and sanitation efforts. Underground exclusion barriers should only be sealed after several consecutive days without new trap catches or fresh burrowing.
Will filling rat holes with dirt stop them from coming back?
Simply kicking dirt back into a burrow hole will not deter rats; they can dig out a soft dirt plug in minutes. To permanently seal burrows, install continuous hardware cloth or fill deep entry points with coarse gravel topped with wire mesh.
Conclusion
Getting rid of rats under a deck or shed requires a methodical approach: eliminate food attractants, trap the existing rodents, and build hardware cloth barriers underground. By taking these practical steps, you can successfully reclaim your outdoor living space and protect your property from future rodent infestations.