Published: Aug 02, 2011 12:40 AM EDT
Updated: Aug 01, 2011 9:01 PM EDT

CAPE CORAL, Fl. - They can grow up to seven feet long, can run almost 20 miles an hour, and if you live in Cape Coral, they might be in your backyard. Nile monitor lizards were first seen in the wild in Cape Coral, about 20 years ago.

It's believed they were let loose on purpose by a pet store owner looking to make a profit. Ever since then, the city has been trying to eradicate them.

"If you live in the southwest portion of Cape Coral and if you live on a canal, chances are you'll see one of these," said Environmental Biologist Harry Phillips.

Monte is a monitor living the simple life at the Cape's Rotary Park. His species is carnivorous, but also has an appetite for eggs, posing a threat to native wildlife such as Burrowing Owls and turtles.

"They've had a chance to grow and multiply, and now they're a nuisance to residents that are living here," said Phillips.

City officials are trapping the large lizards. Its estimated 1000 of them live in the Cape, concentrated in the southwest area.

"It's hot, it's wet, there's a lot of frogs out - a lot of their diet that normally these things eat - this is the time of year we start getting phone calls," said Phillips.

This year, trapping numbers are down from about 70 a week in years past to half that.

"It could be the fact that maybe the weather had an effect on them this past winter - but also - maybe there aren't as many residents in Cape Coral because of all the foreclosure homes," said Phillips.

The city would like to eradicate all monitors but they don't see that happening. Right now, they want to control their populations.

Contrary to what some people believe, Nile monitors are not poisonous. If you see one, you are encouraged to call Cape Coral's Environmental Resources Division. Their phone number is (239) 547-0785.