Officials in Edgewood, a few miles south of Orlando on Lake Conway, have been trying to trap a 4 1/2-foot African Nile monitor lizard that has been spotted in recent weeks in backyards and even taking dips in swimming pools. Smaller lizards have also been caught or killed, including one that made its way into a house through a dryer vent and got stuck in a pipe, The Orlando Sentinel reported.

The lizards have become entrenched in some areas in Florida, including Sanibel Island. Biologists believe that they were originally pets.

But the African Nile monitor grows to be as much as 7 feet long, and it is fast and powerful, with sharp claws. The females lay up to 80 eggs at a time.

"They make terrible pets," biologist Gregg Klowden, said.