"The rabbits became strange in many ways, different from other rabbits. They knew well enough what was happening. But even to themselves they pretended that all was well, for the food was good, they were protected, they had nothing to fear but the one fear; and that struck here and there, never enough at a time to drive them away. They forgot the ways of wild rabbits. They forgot El-ahrairah, for what use had they for tricks and cunning, living in the enemy's warren and paying his price?"
Fiver, Watership Down