I forced my mind to rational places initially; tree branch scraping against the roof, ice falling off a tree onto the roof, etc. However, the more I thought about it, the more these explanations explained nothing at all. It wasn't a windy night, there aren't that many tree branches above our house, and (while we did get ice few day ago), temperatures haven't been warm enough to warrant any ice melting to fall on the roof. I eventually woke up the hubby to go to bed and just as he rejoined the land of the living..."thump," another one. Another "thump" minutes later definitely caught his attention. We got ready for bed, got underneath the covers, and turned out the light. It was then that my mind began to consider the irrational; we're talking poltergeist, ax murdering neighbors, blood thirsty mountain lion pouncing on the roof...it got ridiculous, let me tell ya. There's something about the dark that turns me into the largest chicken you've ever seen.
After laying in bed for a few minutes, wide awake, straining to listen for the phantom thumps, hubby asked if I wanted him to go outside and take a look. My response, "Hell no! I've seen the movies! I know what happens! Stay in here!" Irrational, yes. Ridiculous, yes. I didn't care, I wasn't losing my husband to Santa-poltergeist-lion-ax murderer. I even went and got Little Man from his room and had him sleep with us, that's how freaked out I was.
I don't know when or how, but eventually I fell asleep. After about 17 cups of coffee that next morning, I hauled myself into work. While talking with one of my co-workers, she casually mentioned, "Hey, was your house popping last night? We kept hearing something that sounded like stuff falling on the roof."
After talking a few more minutes and comparing notes on our jacked up, popping, thumping, creepy-acting houses, we decided to do some research. Which means a Google search. Turns out, this is a legitimate thing! When warm air from inside the house meets frigid air from outside the house, thermal expansion and contraction can occur, causing the mysterious sounds we both were hearing at our respective homesteads! Bam! Mystery solved! Next time your house makes creepy noises, do some internet research before jumping to irrational conclusions...your sanity will thank you!