My puppy is 7 months old now & is a little star. I never had any troubles training him. He picked up toilet training very quickly and within a week he would press his wee tiny self up against the door to get outside. I have an enclosed garden and live in a bungalow, which probably did make training easier. I never bothered with puppy pads, as soon as he needed to go, I took him outside. I was so proud lol at how well he done. During the night when he was little I kept him in his bed in my room so that as soon as I heard him move, I could take him outside at night also. Now he never gets up at night and sleeps well past mid day, lazy bones. He also learned to sit after 1 training session (which was 15-20) mins. Giving a paw took a bit longer, he knew what to do but never always done it. Now he can give both on command. He also learned to lie down on command quickly. Honey roast ham done the trick!! Chihuahuas are very smart and love to learn!