Today I was playing a video game and I heard a weird muffled sound come from my BP's tank. I stopped after the second time I heard it, and listened. It was just a loud, muffled-ish puff. I bent down to look at him, and when he did it again, it was like his whole body moved, like he was really forcefully exhaling or something. It's not a whistle, and I didn't see any mucus build up. It happened maybe six times total before he stopped, with maybe 1 minute intervals in between each puff. If this something to worry about? Is he okay? Are there problem signs I should watch out for for the next few days?