My 6 month old yorkie boy wakes up every morning at 3:30-4 a.m. yelping. Yes, it is to be let out to pee. I've gotten the advice that his bladder is too little to last all night and we've taught him to go to the back door to potty so that's why he's yelping. Well, I tried getting up with him as soon as he yelped to let him out and soon he was yelping every two hours all night long! So...someone, tell me that even though he is still only 2.5 pounds, his bladder will eventually be able to go the whole night without expoding onto our laundry room floor!! He lasts during the day while we're at work (6:30 a.m. until 12:30 p.m. lunch) without peeing.