Respiratory infection?

[NewbieLizard43]

My 2 year old Bearded dragon keeps slightly opening his mouth from time to time. He didn't seem to do this before, but now he does it frequently. Im very worried about his health, although this three months that I've had him, he has been relatively active and wanting to come out. Today I heard a weird ticking sound emitting from his tank, and Im not sure if its the crickets or him since I keep them close.
Here are is a photo:
https://www.beardeddragon.org/media/18020/full

I am planning on doing a vet check this week or the next.
Could my beardie have an infection? Or is this a behavior I didn't know about?

 

[NewbieLizard43]

PS: I keep the crickets in a container below his tank. I make sure no cricket remains on the tank after each feeding.

 

[CooperDragon]

I wouldn't worry too much if he doesn't have a lot of excess mucous around his nose or mouth. Since he is active instead of lethargic he is probably OK. It's always good to have a wellness visit to the vet when you can though.