Scientists' concern is growing about the advance of zombie animals.

In rural areas of the northeastern United States, an unusual phenomenon is attracting the attention of neighbors and specialists. Squirrels with strange bumps, hair loss, and a sickly appearance have started to appear in gardens, parks, and wooded areas, which has raised concerns among communities accustomed to living alongside these rodents. The case is reminiscent of the recent episode of the so-called "zombie rabbits" detected in Colorado, creating an atmosphere of alarm and questions about the health of local wildlife.

The first reports about these squirrels came from the state of Maine during the summer of 2023, in areas near the Canadian border. According to neighbors, the animals had warts on their faces, around their mouths, and in some cases, even in the genital area. The images quickly circulated on social media, where users coined the term "zombie squirrels" because of their altered appearance.

In an interview with Bangor Daily News, biologist Shevenell Webb from the Maine Department of Inland Fisheries and Wildlife confirmed that these are cases of squirrel pox, caused by the Leporipox virus, also known as fibromatosis.  "I can't say it's super common here, but it's not unusual to see them here and there from time to time," she explained.

What is fibromatosis and how does it affect wildlife?

The phenomenon is not new to the scientific community. According to the Indiana Department of Natural Resources, fibromatosis is a viral disease that is mainly transmitted by insect bites, and it usually affects rabbits, hares, and occasionally squirrels.

In these animals, the disease manifests as skin tumors that can reach up to 25 millimeters (0.98 inches) in diameter. Although the appearance is striking, authorities assure that in most cases it doesn't compromise the animal's survival.  "In exceptional cases, the tumors can progress to internal organs, weakening the animal and making it lethargic," experts clarify.

Is there a risk for humans or pets?

Concern among residents quickly spread to social media, where many wondered if these diseases could be transmitted to people or domestic animals. However, specialists rule out that scenario. Fibromatosis doesn't affect other species, including dogs and cats, so it doesn't pose a danger to those living near these areas.