my new rat seems to be constantly chattering and sneezing? I've had him a week and a half maybe. He came from a sort of crowded petstore cage. I haven't noticed any red mucus or any other symptoms but I'm still worried. He sneezes usually once or twice every few minutes, I'm assuming thats not normal. He often chitters and "clicks" and today my uncle brought it to my attention that he occasionally dribbles on you. He's very active and not in the least sleepy or lethargic. Could it be a URI?