Several residents of a San Rafael, California, neighborhood say they're being terrorized by attack squirrels that come "out of nowhere."

"I was just walking along, and suddenly, there's a squirrel attached to my thigh, just clomped on to my thigh," Joan Heblack, who lives in the Lucas Valley neighborhood, told KRON. "I look down and I was like, ‘What is that?' I said, ‘Get off, get off!' I was trying to brush him off. And he was just clinging more and biting."

While Heblack was eventually able to remove the squirrel and seek medical attention, her neighbors nearby are reportedly thinking twice before going outside.

Another resident who lives a few doors down from Heblack said her husband was attacked by a squirrel Friday when he tried to shoo it away from their fence.

"She took a big chunk of the wood, and we thought, 'Oh my gosh, she's hungry or something,'" Marie Ayoob told KRON. "Joe, my husband, took off his cap and hit it so it could go away. Well, she turned around and just jumped on his head."

Ayoob said her husband was scratched behind his ear, and he's not the last person to encounter an aggressive squirrel – five of her neighbors have also been attacked.

The neighborhood is now plastered in flyers that warn about the squirrel attacks, as well as the potential damage the animals can do with their teeth and claws. The flyers state that the "very mean squirrel" appears "out of nowhere" and that "several have gone to the ER for severe lacerations."

"This is not a joke," the flyers stress.

A spokesperson for WildCare, a wildlife hospital and advocacy organization, told the outlet in a statement that aggressive behavior in squirrels is nearly always because they've been fed by humans.

"WildCare has received numerous calls about a squirrel attacking residents in the Lucas Valley neighborhood of San Rafael," the spokesperson said. "Unfortunately, the squirrel is most likely approaching people and biting them because he was raised by people, or has been hand-fed by a human, but is now on his own, uncertain about how to forage, and desperate for food. Squirrels are naturally shy animals."

The organization said a baby squirrel that is raised by humans doesn't understand why some people feed it and others do not.

"The lesson here is don't feed wildlife, and always bring orphaned baby animals to WildCare for care," the spokesperson told KRON. "We make sure they remain wild."