A Philadelphia family woke up Saturday to find a skinny puppy in their living room. The dog definitely hadn’t been there the night before, and all the windows and doors were closed.

Upon finding the pup, Jack Jokinen’s first reaction was alarm: “Very freaky,” he told Philadelphia TV station KYW.

But once they figured out what had happened, the family decided to keep her.

The mystery was solved by surveillance video from outside the Jokinen house in the Fishtown neighborhood.

It shows the little dog, at around 3:15 a.m. Saturday, limping along the sidewalk in the chilly winter night. She walks up the steps to their front stoop, where the door is ajar, and then stealthily walks inside.

Twenty minutes later, Jokinen’s neighbor walks by and notices the door open.

“I yelled inside to see if somebody was there,” neighbor Steve Griendling told the KYW reporter. “The dog didn’t even respond.” He pulled the door closed and went on his way.

Jokinen suspects he didn’t shut the door all the way before going to bed Friday and that it blew open in the night.

Now, even though the Jokinens have another dog, George, and a 1-month-old baby, they’re going to keep the puppy. They’re calling her Suzy.

She plays well with George and even looks a little like him. She has been to the vet and treated for several ailments, the bill for which was $1,000.

“She’s in a warm house. … She’s getting cuddles and a soft bed and a loving environment. At a minimum, that’s what we can give,” Jokinen said of the prowler who found a forever home.