This isn't Carolina's first time in a barracks-like situation and while it's been a while, she's still pretty sure she can spot when someone thinks they're funny. Since that seems to be the case here, she doesn't need to sleep, just to figure out who's responsible. Which means waiting, wandering in and out a few times late at night, until she's eliminated most of the floor as suspects, trying to be casual in her conversations but honestly, casual is still awkward for her. Periodically wandering the floor in silence suits her better.

Eventually she's going to find Sans though, coming out behind him on the balcony, leaning against the doorframe with her arms crossed over her chest, covering the loose t-shirt she should be sleeping in. If she was going to sleep at some point, that is.

"Hey, you haven't noticed anything odd happening with the bedding today, have you?"