Animals can kill without incurring Sin, Humans cannot

Human beings are not meant to quarrel like cats and dogs. They must be intelligent enough to realize the importance and aim of human life. The Vedic literature is meant for humanity and not for cats and dogs. Cats and dogs can kill other animals for food without incurring sin, but if a man kills an animal for the satisfaction of his uncontrolled taste buds, he is responsible for breaking the laws of nature. Consequently he must be punished.

– Srila Prabhupada, Sri Isopanishad Mantra 1