translation.en: Now, they don't develop morality to the point of carrying the shopping bags of little old mice across the street, but their improved environment results in healthy, sociable behavior.
translation.zh: 它们当然不会发展出 为老老鼠过街提购物袋的 文明举动来， 但是他们所处的良好的环境导致了 健康的社会行为。