Just a moment ago, I was getting ready to take my week olds out of the brooder and let them run around the room and stretch their legs. I heard this noise coming from inside the brooder and I thought it was either straw or some water hissing on the heat lamp (which has never happened). Then I noticed this sizzling sound was coming from one of my ducklings. It's almost as if it's gas rumbling, but it's a very loud sizzling sound. He did poop just after I put him down, so he's not constipated. What on earth could it be? I'll try to attach the video from my phone.