From this story in the San Jose Mercury News:
They slithered behind the walls at night and released foul-smelling musk into the drinking water. And they were so numerous that Ben Sessions once killed 42 in a single day. Shortly after buying their dream home, Sessions and his wife discovered it was infested with thousands of garter snakes. For the next three months, their growing family lived as if in a horror movie. More than a year after they abandoned the property, the home briefly went back on the market, and they fear it could someday attract another unsuspecting buyer. The five-bedroom house stands on nearly two pastoral acres in rural Idaho, about 125 miles southwest of Yellowstone National Park. Priced at less than $180,000, it seemed like a steal. But the young couple soon learned they would be sharing the home with reptiles at least two feet long that had crawled into seemingly every crevice.
_"...When they bought the house, the Sessions signed a document that noted the snake infestation. They said they had been assured by their real estate agent that the snakes were just a story invented by the previous owners to leave their mortgage behind. They soon learned that nearly everyone else in this tiny college town knew the snakes were real. "I felt bad," said Dustin Chambers, a neighbor. "By the time we knew someone had bought it, they were already moving in. It was too late." Among locals, the property is known simply as the "snake house," he added.