In Animal Farm, in what chapter does Napoleon take the puppies and is there another way that he has power over the other animals?
Napoleon takes the puppies of Jessie and Bluebell very early in the book - section three. This shows that Napoleon right from the beginning was thinking about how to gain power. This is an important point to bear in mind, because he was more scheming than Snowball and any other animal for that matter. Here is the text:
It happened that Jessie and Bluebell had both whelped soon after the hay harvest, giving birth between them to nine sturdy puppies. As soon as they were weaned, Napoleon took them away from their mothers, saying that he would make himself responsible for their education. He took them up into a loft which could only be reached by a ladder from the harness-room, and there kept them in such seclusion that the rest of the farm soon forgot their existence.
Now as for your second question, there were many other ways in which Napoleon sought to gain and maintain power. First, he used rhetoric. He had Squealer who would always spin things to his favor. Also because Squealer was such a great speaker, he persuaded the animals that he was always right. In fact, this was one of Boxer's mottos.
Second, he limited the education to pigs so the other animal could not read. If knowledge is power, than he had all of it. This is why none of the animals could really create any type of revolution. The only one that could have was driven out - Snowball.
Finally, when Napoleon had things in place, he could do whatever he wanted. At the end of the book, he turned into a human and the animals did nothing, because they could do nothing - so complete was his power.
It is in Chapter Three of Animal Farm that Napoleon takes the puppies. These "nine, sturdy puppies" belong to Jessie and Bluebell and Napoleon takes them away from their mothers as soon as they are weaned. He claims to want to educate the puppies but, later on, we see that he has trained them to act as his personal (and very violent) bodyguards.
Aside from training the puppies in this manner, Napoleon uses his cunning to seize power over the other animals. We see this most clearly at the end of Chapter Two when Napoleon distracts the other animals so that he can steal the cows' milk:
"Never mind the milk, comrades!" cried Napoleon, placing himself in front of the buckets. "That will be attended to. The harvest is more important."
By using the harvest (an event of extreme importance) as a distraction, Napoleon illustrates the depth of his natural cunning and powers of deception. It also shows that he considers the pigs to be superior to the other animals and deserving of better rations, like milk and apples. It is this which belief which drives his bid for absolute power on the farm.
Napoleon takes the puppies away to give them his own brand of education in chapter 3. When they resurface, they act as his personal police protecting him, doing away with his enemies, and allowing himto rule Animal Farm through fear tactics.
The dogs are not, however, the only way Napoleon mantains power. Arguably, an even more effective means of attaining and maintaining his absoulte power is through propaganda. For this, he uses Squealer to continually justify his actions to the other animals and convince them that Napoleon's changing and breaking of the commandments, as well as his other policies that are seen as contrary to Animalism, is in fact in the best interest of the animals and the farm.