Why “Zombie Squirrels” Are Suddenly Everywhere
Homeowners across the United States and Canada have recently reported sightings of squirrels with unusual and alarming appearances. These rodents are covered in lumps and sores that can make them look disfigured or even reminiscent of creatures from horror stories. The condition has caused concern among wildlife enthusiasts and casual observers alike, particularly because it is so visible and disturbing.
The first reports of these strange-looking squirrels date back to 2023, when residents began posting pictures of the animals on social media. Observers noticed that the squirrels had hairless patches and growths on their faces and bodies, giving them the nickname “zombie squirrels.”
Via GreaterGood
The phenomenon initially attracted attention in urban and suburban areas, where people were most likely to encounter these animals in their gardens and parks. These early sightings helped researchers track the spread of the condition across various regions. Experts have identified the culprit behind this unusual appearance as a virus called leporipoxvirus.
Understanding Squirrel Fibromatosis
Squirrel fibromatosis is characterized by the development of tumors on the skin of infected animals. These tumors are generally noncancerous and can vary from small, barely noticeable lumps to large growths several centimeters in diameter. The tumors can appear anywhere on a squirrel’s body, including its face, limbs, and tail.
Via The Independent
Their appearance is often distressing to humans, but in most cases, the tumors do not cause significant harm to the animals themselves. The impact of these tumors depends largely on their size and placement. When the fibromas are situated away from critical body structures, they may not interfere with the squirrel’s normal activities.
In such cases, the animals can eat, move, and interact with other squirrels as usual. However, tumors located near the eyes, mouth, or joints can affect essential functions like vision, eating, and mobility. These complications can reduce the animal’s ability to survive in the wild and make it more vulnerable to predators.
Via Gizmodo
Rarely, the virus may infect internal organs such the kidneys, liver, and lungs. When this happens, it can interfere with regular body processes and even cause death. Recovery may be made more difficult if the growths get contaminated with bacteria or fungi, which can lead to secondary illnesses. Despite these possible dangers, the majority of squirrels with fibromatosis recover fully once the tumors gradually recede.
How the Virus Spreads Among Squirrels
Direct animal contact and vectors like insects are the main ways that the leporipoxvirus that causes squirrel fibromatosis spreads. Biting insects, including mosquitoes and fleas, can carry the virus from one squirrel to another. When an infected insect bites a healthy squirrel, the virus can enter the body at the bite site and begin forming tumors.
Via Scientific American
Squirrels can transmit the virus to one another through saliva and other bodily fluids during social interactions or aggressive encounters. Transmission is particularly common in areas where squirrels congregate, such as bird feeders or communal feeding sites. When multiple squirrels feed from the same location, the virus can easily pass from one animal to another.
This is why wildlife experts advise caution when setting up feeding stations, as they can inadvertently promote the spread of the virus. Even well-intentioned efforts to feed and care for wildlife can increase the risk of transmission if proper precautions are not taken. Despite the highly visible nature of the infection, humans cannot contract the virus from squirrels.
Via Smithsonian Magazine
Pets such as dogs and cats are not at risk from exposure. The virus has been experimentally transmitted to rabbits and woodchucks in laboratory settings, but natural infections in these species are extremely rare. This makes the disease a concern primarily for squirrels themselves rather than for humans or domestic animals.
The Role of Human Activity in the Spread of the Virus
Human behavior can influence the prevalence of squirrel fibromatosis, even when intentions are good. Wildlife biologists have observed that feeding squirrels in gardens and parks can create hotspots for viral transmission. When infected squirrels leave saliva or other fluids on feeders, the virus can be picked up by healthy animals that visit the same feeding sites.
Via New York Post
Standing water is another factor that can indirectly promote the transmission of the virus. Mosquitoes, which act as carriers, breed in stagnant water. Gardens and backyards with unmaintained water sources can increase the number of mosquitoes in the area, providing more opportunities for the virus to move between squirrels.
Public concern often peaks when images of affected squirrels circulate online. While these images can be alarming, biologists emphasize that the condition is not usually fatal and that the majority of squirrels recover without human intervention. Observers are encouraged to maintain a safe distance and avoid handling infected animals, as contact can spread the virus among the local squirrel population.
Via Tyla
Symptoms and Recovery of Infected Squirrels
The most visible symptom of squirrel fibromatosis is the presence of fibromas, which appear as wart-like growths on the skin. These tumors can develop singly or in clusters, sometimes covering large portions of the body. Hair loss often accompanies the growths, creating bald patches that add to the animals’ unusual appearance.
In severe cases, the tumors can become oozing sores, though these rarely threaten the animal’s life unless vital functions are compromised. Even when the growths appear alarming, most squirrels remain active and continue normal behaviors while healing. Recovery from the disease typically occurs over four to six weeks. The tumors gradually shrink and the skin heals, leaving minimal scarring in many cases.
Via News18
Even squirrels that experienced more extensive growths often regain mobility and normal behavior once the infection resolves. Social behaviors, such as foraging and interaction with other squirrels, usually resume without long-term impairment. This resilience explains why the population numbers of gray squirrels in North America have not been significantly affected despite the spread of the virus.
While death from fibromatosis is rare, it can occur if tumors interfere with critical body functions. Growths near the eyes, mouth, or major joints may prevent feeding, moving, or seeing, and internal infections can disrupt organ function. Predation can also increase for squirrels debilitated by the disease.
Via Forbes
Preventing the Spread of Squirrel Fibromatosis
Preventing the spread of the virus requires careful management of both human activity and environmental factors. Wildlife experts recommend avoiding close contact with squirrels, especially those showing visible signs of fibromatosis. Touching infected animals or contaminated surfaces can facilitate virus transmission among the local population.
Public awareness about these guidelines can reduce unintentional contributions to disease spread. Reducing mosquito populations is another important preventive measure. Eliminating standing water around homes and gardens can limit the breeding of mosquitoes that carry the virus from one squirrel to another.
Via Wildlife Online
Gardeners and homeowners are encouraged to inspect their yards regularly and take proactive steps to minimize insect habitats. These measures help slow the transmission of the virus while allowing affected squirrels to recover naturally. Experts also caution against congregating multiple squirrels in small areas.
Differences Between North American and UK Squirrel Viruses
It is important to distinguish the North American leporipoxvirus from similar viruses found elsewhere. In the United Kingdom, the parapoxvirus, sometimes called “squirrelpox,” affects red squirrels and can be fatal. In contrast, the North American strain is generally mild and rarely causes death. Confusing these two viruses can lead to misunderstandings about the threat level posed by infected animals in the U.S. and Canada.
Via A-Z Animals
Unlike the UK version, the North American leporipoxvirus does not appear to threaten population stability among affected squirrel species. It primarily causes temporary disfigurement rather than severe illness or mortality. The tumors it produces are localized and self-limiting, and outbreaks are mostly of cosmetic concern rather than ecological emergency.
Public Response and Observations
Social media has played a large role in raising awareness about zombie squirrels. Residents have shared images of gray squirrels with extensive fibromas, prompting curiosity and concern. Many posts note the alarming appearance of the tumors, but also highlight that the animals remain active and continue to forage despite their disfigurement.
Via Mammal Society
Such observations provide informal documentation of the condition and help researchers track its prevalence across regions. Wildlife biologists emphasize that while the disease is startling in appearance, it is rarely life-threatening. Observers are advised to appreciate the animals from a distance and avoid interventions that could spread the virus further.
Videos and photos shared online often show squirrels recovering from the infection, demonstrating their resilience and ability to return to normal behaviors after the fibromas regress. The combination of human curiosity, social media visibility, and concentrated squirrel activity has increased public attention to this natural phenomenon.
Via Natural History Museum
Discover the Truth Behind the Zombie Squirrel Phenomenon
Zombie squirrels have captured attention across North America due to their unusual appearance, but understanding the underlying causes reveals that these animals are largely unharmed. Leporipoxvirus causes temporary fibromas that make squirrels look disfigured, yet most recover fully without human intervention.
The disease is primarily a cosmetic concern rather than a fatal threat to the population, and it does not pose a risk to humans or common household pets. Human activity, such as feeding squirrels and creating mosquito-friendly environments, can influence the spread of the virus. Awareness and careful management of these factors can reduce transmission rates while allowing squirrels to recover naturally.
Via MSN
Observing the animals from a distance, avoiding direct contact, and minimizing vector habitats are all effective strategies. Responsible observation and respect for natural processes are key to coexisting with these fascinating creatures as they navigate a viral challenge that is temporary and generally harmless.
