>> “By the way, how did they cross the Panama Canal to go into south America to breed?” <<
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By walking across the tops of the lock gates silly!
What really happened was this: (I just finished doing some research on this.)
These folks who bred like rats could neither swim nor walk on water. Therefore, they trekked across the locks. This was on the Pacific side of the Canal.
As they got off the locks and some yards away, a few got smacked and mashed by a train going to the Atlantic side.
Some managed to escape this tragedy and continued on in their mission to reproduce as if there were no tomorrow…until the Spaniards came and wiped most of them out in parts of South America.
And there. I did my homework.