OK, yes, I'll take literally any excuse to tell this story.
Back in the day when we had landline telephones (kids, ask your grandparents), my dad worked for the phone company sending technicians out to people's houses to do installations and repairs. Sometimes, if you were adding new phone jacks, you would go under the house and run a wire up through the floor.
The technician arrived at the house, found the entry to the crawlspace, and crawled inside. Then he crawled back out, walked to the front door, knocked, and when the homeowner answered, said, "Ma'am, I'll be happy to finish installing your phone line as soon as you remove the alligator."
"Oh," she said, "I was wondering where that went."
See, at this time you could go to Florida and buy a baby alligator as a souvenir. Most of them didn't live terribly long in their new homes, but this woman's son had apparently gotten his pet alligator to a reasonable size before it escaped and went under the house, where it survived the Pittsburgh winters by curling around the water heater and eating rats.
I do not know the ultimate fate of the alligator. I do know that even in quite cold climates, the chance you'll find an alligator in your crawlspace is low, but never zero.