Pack rats (Neotoma species), also known as woodrats, are nocturnal rodents common across North America. They are distinct from common Norway or roof rats due to their larger size, hairy tails, and habit of collecting debris, which earned them the nickname “pack rat.” This hoarding behavior results in the construction of large, messy nests called “middens” in sheltered outdoor locations. Outdoor infestations are problematic because the rodents cause property damage by chewing on wiring and carry parasites and diseases, including Hantavirus, posing a risk to people and pets.
Identifying and Eliminating Outdoor Attractants
The first step in managing an outdoor pack rat problem is altering the environment by removing the resources that attract them: sheltered nesting sites and readily available food. They are attracted to any form of clutter that provides a dark, secure place to build their large middens.
Immediately clear away debris such as woodpiles stacked against the house, old furniture, and construction waste. Store necessary items on elevated platforms at least 18 inches off the ground. Since pack rats are adept climbers, trim tree branches and dense shrubbery back to create a buffer zone, preventing easy access to structures like sheds or garages.
Pack rats are opportunistic feeders, consuming seeds, nuts, and berries, but they readily take advantage of human-provided food sources. Secure all garbage cans with tight-fitting lids and rinse out recyclables to remove food residue. Pet food should never be left outside overnight, and bird feeders should be removed during an active infestation, as spilled seed provides a concentrated food source.
Promptly pick up and dispose of fallen fruit from trees and vegetables from gardens. While pack rats acquire moisture from vegetation, eliminate all sources of standing water. This includes repairing leaky outdoor faucets and ensuring that pet water dishes are brought inside before dusk.
Active Removal Strategies
The next phase involves actively removing the existing pack rat population through trapping, which is the most effective method for control. Standard snap traps designed for rats are highly effective because pack rats are less hesitant about approaching new objects than other rodent species.
Use sticky baits that force the rodent to tug on the trigger plate, such as peanut butter mixed with rolled oats or dried fruit tied securely to the trigger. Place traps directly along active travel paths, often near walls, fences, or under dense cover, as these rodents prefer to hug vertical surfaces. To protect non-target animals, secure all traps inside a protective box or a specialized, tamper-resistant bait station.
Avoid using rodenticides or poison baits in an outdoor setting. Pack rats frequently hoard bait rather than consuming it immediately, which delays control and increases the risk of the toxin being carried away. This creates a high risk of secondary poisoning for predators like owls, hawks, and coyotes that may eat the poisoned rat. Snap traps offer a non-toxic and efficient method of control.
Securing Structures and Sanitizing the Area
The final step for long-term control focuses on exclusion and meticulous cleanup to prevent future infestations. Pack rats can squeeze through surprisingly small openings, so all structures, including sheds, garages, and utility closets, must be thoroughly inspected and sealed. Any gap larger than a quarter-inch should be plugged immediately using materials the rodents cannot chew through.
Effective exclusion materials include heavy-gauge hardware cloth, sheet metal, or concrete mortar to fill foundation cracks. Cover vents and openings for pipes or utilities with galvanized steel mesh, securely fastened to the exterior surface. Maintaining structural integrity ensures that new pack rats cannot move in to replace the ones that were removed.
After the infestation is eliminated, the area must be sanitized, focusing on removing middens and contaminated materials. Pack rat droppings and urine can transmit serious diseases, such as Hantavirus Pulmonary Syndrome, through airborne dust particles. Always wear heavy-duty gloves and a respirator or N95 mask before beginning cleanup.
The middens, which are large piles of sticks and debris, should be thoroughly soaked with a household disinfectant or bleach solution before being carefully bagged and disposed of. Never sweep or vacuum dry droppings or nesting material, as this aerosolizes viral particles. Wipe down contaminated areas with the disinfectant solution to neutralize any remaining pathogens.