Ground squirrels are burrowing rodents that spend the majority of their time underground. They are smaller than tree squirrels and have shorter, less bushy tails. Ground squirrels create extensive tunnel networks that can stretch anywhere from five to thirty feet in length and up to four feet deep. These burrow systems undermine sidewalks, foundations, and irrigation lines, while the animals themselves eat seeds, plants, and fallen fruit, causing significant damage to lawns and gardens. Successfully managing an infestation requires understanding these habits and implementing a strategy that progresses from making the environment unappealing to active removal.
Modifying the Environment to Deter Ground Squirrels
The first step in controlling a ground squirrel population involves making the area less attractive for them to inhabit and forage. Ground squirrels are highly dependent on cover and readily available food sources, so eliminating these factors encourages them to seek shelter elsewhere. Removing debris piles, rock stacks, and tall, dense ground cover eliminates the safe havens they use for protection and for concealing burrow entrances.
Managing food sources is equally important, as ground squirrels are opportunistic feeders. Bird feeders should be modified to catch falling seed or replaced with squirrel-proof models, and pet food should never be left outdoors. Regularly raking up fallen nuts, fruits, and seeds from trees and shrubs also removes a substantial portion of their diet. Deep tilling the soil in agricultural or large garden areas can destroy existing burrows and disrupt the habitat, making re-establishment difficult.
Physical barriers offer the most reliable form of exclusion for vulnerable areas like garden beds and foundations. Installing hardware cloth or chicken wire mesh around the perimeter of garden plots prevents them from digging up plants. For effective exclusion, the mesh must be buried at least four to six inches deep and extend vertically above the ground to block their digging and climbing attempts. This technique prevents ground squirrels from accessing specific areas.
Active Non-Lethal Removal Methods
When habitat modification is not enough, active non-lethal methods can be used to discourage or remove ground squirrels without causing harm. Taste and odor repellents can be applied to plants and around burrow entrances to make the area undesirable for foraging. Commercial products often contain capsaicin, a compound derived from chili peppers, or predator urine scents, which are unpleasant to the rodents. These repellents must be reapplied frequently, especially after rain, to maintain their effectiveness.
Harassment techniques use sudden, startling stimuli to scare the squirrels away from a specific location. Motion-activated sprinklers, which spray a burst of water when an animal crosses their sensor, are effective at deterring ground squirrels near lawns and gardens. Loud noises or visual deterrents, such as decoys that mimic natural predators like owls or hawks, can also be employed, though their effectiveness often diminishes over time as the animals become accustomed to them.
Live trapping is a method that allows for the physical removal of the animals, typically using wire cage traps baited with foods like nut meats or melon rinds. The traps should be placed near active burrows or along known travel routes, and must be checked frequently to ensure the captured animal does not suffer from exposure or stress. A crucial consideration with live trapping is the legal status of relocation, which is often heavily regulated or outright prohibited. Relocation is often illegal due to the risk of disease transmission or simply moving the problem elsewhere, meaning trapped animals may need to be euthanized on-site depending on local wildlife codes.
Lethal Control Options and Safety Regulations
For persistent or large infestations, lethal control methods may be necessary, but these options carry significant safety risks and are subject to strict regulations. Lethal trapping involves using specialized devices such as rat-sized snap traps or body-gripping traps (like the Conibear style), designed to kill the animal quickly. These traps must be placed strategically, often directly over the burrow entrance, and secured to prevent the squirrel from dragging the trap away.
Safety is paramount when using kill traps, as they pose a substantial risk to pets, children, and non-target wildlife. To mitigate this danger, lethal traps should be concealed within a protective wooden box or container with small access holes that allow only the ground squirrel to enter.
Fumigants are another lethal option, using products like gas cartridges or aluminum phosphide tablets to introduce toxic gases into the burrow system. Fumigation is most effective when soil moisture is high, as the moisture traps the gas within the tunnels, but it must never be used near buildings due to the risk of gas leaking into inhabited structures.
Toxic baits, such as those containing anticoagulants or zinc phosphide, are effective at reducing large populations, but they introduce the highest risk of secondary poisoning. Non-target animals, including domestic pets and local wildlife, can be harmed by eating the poisoned ground squirrels or by accessing the bait directly. These chemical controls are highly regulated by the Environmental Protection Agency (EPA) and often require a professional license or adherence to guidelines, such as placing bait only in tamper-resistant stations. Consult local and state wildlife authorities before implementing any lethal control measure, as laws vary greatly regarding permissible removal methods.