Scott took ponies, motorised sleds and ordinary sleds, which he and his men pulled. He thought that the number of animals overworked and killed should be held as low as possible and considered his rival Roald Amundsen's approach as cruel. Amundsen, on the other hand, killed dog after dog to feed himself, the men and the rest of the dogs. He did not feel bad about it. The ponies helped travelling part of the way to the pole, but some of them were so stubborn that the expedition members, especially Lawrence Oates, lost much energy that was needed to get back from the pole. The motorised sleds (which worked well at the start) eventually froze up. The dogs, of which there 36, were left behind on the final attempt on the Pole.