I woke up today to find Roc missing, with the cage door open. The way her cage is, it can't be opened from the inside as it works something like a draw bridge. I spent the morning looking for her, and eventually found her sleeping while perched on top of my dresser's mirror. I had to look away to get her down, but thank goodness I eventually did.
I kept a good eye on her the rest of the day, and caught her wedging her beak between the bars of the cage and door, trying to push it open. I startled her by saying her name, and hopefully this won't be a common occurrence. I might just have to go buy a lock to make sure.