Rhys Adams, 9 holds a 5-legged frog that she and her neighbourhood kids found in some wetlands behind their London, Ontario subdivision. Adams says they are always outside catching snakes and frogs and is afraid that pollution caused the extra leg on the frog. (Sun Media/Mike Hensen)

Grossed-out, excited and then concerned -- that's how a nine-year-old London girl felt when she pulled from her backyard pond a frog with five legs.

It's not that Rhys Adams is squeamish.

For the last week, she's been standing barefoot in the mud with two brothers, ages eight and 10, as the siblings grabbed six snakes and nearly two dozen frogs in the pond next to their new home on Firefly Drive in North London.

But Monday afternoon, as Rhys and her brothers crowded around a bucket with her latest catch, the nine-year-old let out a scream.

"Ahhhhh! It has five legs!"

The siblings ran through the yard screaming in excitement, but then Rhys and her mom Kim began to wonder how a frog with an extra limb came to be in their pond.

"I'm thinking there is some sort of pollution," Rhys Adams said with the earnest seriousness of a child.

"Maybe the water should be tested," Kim Adams said.

Their suspicion may be on the mark -- a recent study published in the Proceedings of the National Academy of Sciences of the United States found a link between excess nitrogen and phosphorus found in farm runoff is linked to parasites that can cause deformities in amphibians.

After keeping the frog in a damp environment in the garage overnight, the family let the creature go yesterday.

jonathan.sher@sunmedia.ca