FORT LAUDERDALE, Fla. — Non-native iguanas are multiplying so rapidly in South Florida that a state wildlife agency is now encouraging people to kill them.

A Florida Fish and Wildlife Conservation Commission news release says people should exterminate the large green lizards on their properties as well as on 22 public land areas across South Florida. It doesn’t say just how civilians should try to kill them.

“Homeowners do not need a permit to kill iguanas on their own property, and the FWC encourages homeowners to kill green iguanas on their own property whenever possible,” the agency says.

Iguanas aren’t dangerous or aggressive to humans, but they damage seawalls, sidewalks, landscape foliage and can dig lengthy tunnels. The males can grow to at least 5 feet (1.5 meters) long and weigh nearly 20 pounds (9 kilograms).

The commission says female iguanas can lay nearly 80 eggs a year and South Florida’s warm climate is perfect for the prehistoric-looking animals. Iguanas are native to Central America, tropical parts of South America and some Caribbean islands.