REXBURG, Idaho — 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.

While setting up a chicken coop, Sessions lifted a piece of sheet metal and was startled to see a pair of snakes slither away. A few days later, he found more and soon started to collect dozens in buckets. At times, there were so many in the yard that the grass seemed to move.

If he rapped a stick against the roof overhang, he could hear dozens scatter, their scales sliding against the aluminum. After he removed some panels of siding, dozens of snakes popped out. When he made his way through the crawl space to investigate further, he found snakes everywhere.

That’s when he realized his family was probably living atop a garter snake den where the nonpoisonous reptiles congregate in the fall and winter.

Sessions quickly developed a daily snake-fighting routine. Before his pregnant wife and two small boys got out of bed, he would do a “morning sweep” through the house to make sure none of the snakes had gotten inside. One day, his wife screamed from the laundry room, where she had almost stepped on one. He rushed in to find that she had jumped onto a counter.

“I was terrified she was going to miscarry,” he said.

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.

The pests were impossible to escape no matter the hour of the day.

At night, the Sessions would lie awake and listen to slithering inside the walls. During the day, the family often had to eat out because their well water smelled like the musk released by the snakes as a warning to predators.

But because of the paperwork they had signed, the couple had little recourse when they decided to flee the home. They filed for bankruptcy, and the bank foreclosed on the house.

The Sessions left in December 2009, the day after their daughter was born and just three months after moving in.