Can a pipe creak in the wall?

We've owned our house in Illinois for 6 months and when it's even gently windy outside, a loud groaning, creaking sound comes from an "outside-facing" wall of our daugher's bedroom. The sound does not happen when it gets particularly cold, nor when it's windless. It's not directly related to flushing or water flow - only to wind (and an outside temperature above freezing). Neither us - nor the former owners - can figure it out. Could it be pipes moving in the wall with the wind, or is it more likely to be a beam of the house creaking? We're stumped -- any and all hypotheses very welcome!

It sounds like a branch rubbing on your house. If not that a loose board.

good luck with figuring it out.