No one on yahoo can give you a direct answer or solve your problem, at least not without inspecting the finch first. I will give you a list of advice that can help.

birds have evolved to hide their illness as it can get them killed in the wild, if you're bird starts showing symptoms its too late.

But your bird hasn't so take him to the vet if this solved by the time you read this, it could be your only chance at saving him.

PS sorry for the **** answer above me.

Hey!

I have had my zebra finch from the day he was born! Now i`ve been noticing that he is a little bit different than usual. i am suspecting that it is Air sac mites but he haven't been showing all symptoms! His eyes aren't closed and he is still flying and jumping around like before BUT his vent area is sometimes ( Not always) Dirty/wet. He is also breathing really fast, Not heavily but fast. And when he is breathing he makes a clicking sound! And he fluffs up himself sometimes but he doesn't remain fluffed. He Fluffs up himself several times and is like chewing on his vent area. Like i said he is still active and flying around! His eyes are always open when he eats and drinks!

Please if u know something tell me!!!!