Hi there, I have a duckling about 3 weeks old that is making a clicking noise. It sounds like it is coming from his beak but is sometimes rhythmic as if it is happening when he is breathing. I haven't noticed and strange behavior changes but I'm worried he is sick. Please let me know if anyone knows what this is! 

I attached a picture of her neck. I’m taking her to an avian vet this week but they were closed today to be able to schedule something so I’m hoping they have availability for the earliest. Her breathing is also kinda heavy, I’m guessing it’s a respiratory infection (possibly bacterial). I even gave her Vetrx but after I gave it to her was when the plucking started so I stopped giving it to her cause it made me nervous that’s what caused the plucking in the first place. Any help would be greatly appreciated!
Whenever I have a sick chicken, I feel the exact same way and constantly check on them. I'm sure your little ducky will be alright, it doesn't sound like she's doing too badly.