Backyard watchers across the United States are alarmed—not by fires or floods this time, but by a wave of squirrels that look straight out of a horror movie. Gray squirrels grotesquely covered in wart-like tumors and pus-filled sores have been turning up across states like Maine and beyond, earning creepy nicknames like “zombie squirrels.” But wildlife experts want to make one thing clear: they’re not a threat to humans or pets—though the sight alone can leave you shaken.
Reports of these eerie sightings have circulated since mid-2023, but summer brought a surge in photos shared across Reddit, X, and neighborhood pages. One resident recalled, “At first I thought it was eating something in my flowerbed—but then I realized it was a growth on its face.” The condition afflicting these animals is squirrel fibromatosis, a viral disease caused by a skin-affecting poxvirus. Though unsettling to look at, the disease usually fades in four to eight weeks without treatment experts explain.
Zombie squirrels prowling my garden—covered in oozing sores. Nature really outdid itself this time. pic.twitter.com/gardenhorror— backyard observers (@naturewatch) August 2025
Wildlife biologist Shevenell Webb of Maine’s Department of Inland Fisheries and Wildlife reassured concerned citizens that, despite their appearance, the squirrels are harmless to people, pets, or birds. The virus spreads through contact with lesions or saliva—often at communal feeding spots where the creatures gather. Webb cautioned: “It’s like a crowded room—if one is sick, others are going to catch it”—and urged everyone to avoid handling affected wildlife, which typically recovers on its own as the recent advisory stated.
To understand how this ties into broader animal health trends, pairs of “Frankenstein rabbits” covered in tentacle-like tumors have also been seen in Colorado, victims of the Shope papilloma virus. Though equally shocking visually, these outbreaks emphasize the invisible viral threats moving through wildlife populations—none of which are transmissible to humans, but serve as living reminders of nature’s weird, wild variability.
Same virus theme: rabbits with tentacles, now squirrels with zombies. What’s next, bird flocks with glowing eyes? pic.twitter.com/naturethriller— WildWatch (@wildlifewatch) August 2025
The virus behind the phenomenon is often confused with squirrelpox—a known threat in the UK that’s rapidly alarming red squirrel populations—but fibromatosis is distinct and mostly non-fatal to North American greys. In most cases, these tumors—but ugly—are superficial, though they can become dangerous if they affect internal organs. One wildlife report noted that such tumors in other parts of the world have led to emaciation and organ failure.
Still, the social dimension is urgent. Bird feeders, those cheerful staples of backyard nature, have become inadvertent hubs for virus transmission. Squirrels leave saliva on uneaten seeds, and others pick up the disease during their visits—turning a symbol of leisure into a vector of contagion. “Beautiful concept,” Webb mused, “but a nightmare when disease rides along with your suet.”
That slideshow where ‘cute squirrels become horror show’. Nature turned glitchy, folks. Don’t share feeders if you see these. pic.twitter.com/wartwatch— Critter Summit (@crittersummit) August 2025
Experts also believe environmental change may be at play. Milder winters, shifting predator populations, and habitat loss can stress wildlife, leaving immune systems weaker and more susceptible to outbreaks. With more of us living close to nature, wildlife disease visibility has skyrocketed—and so have our fears.
Still, there’s no cause for widespread panic—just cautious respect. If you spot a squirrel with sores or warts, most wildlife teams advise leaving it be, maybe disinfecting your feeder and enjoying the birds from afar. In time, these unforgettable “zombie squirrels” will pass away—or on to healthier foliage—leaving stories behind, not pathogens.
