Unhappiness without a cause you never, never find;
   It may be in the stomach, or it may be in the mind.
     - Whitefoot.

Whitefoot the Wood Mouse should have been happy, but he wasn't. Winter had gone and sweet Mistress Spring had brought joy to all the Green Forest. Every one was happy, Whitefoot no less so than his neighbors at first. Up from the Sunny South came the feathered friends and at once began planning new homes. Twitterings and songs filled the air. Joy was everywhere. Food became plentiful, and Whitefoot became sleek and fat. That is, he became as fat as a lively Wood Mouse ever does become. None of his enemies had discovered his new home, and he had little to worry about.

But by and by Whitefoot began to feel less joyous. Day by day he grew more and more unhappy. He no longer took pleasure in his fine home. He began to wander about for no particular reason. He wandered much farther from home than he had ever been in the habit of doing. At times he would sit and listen, but what he was listening for he didn't know. "There is something the matter with me, and I don't know what it is," said Whitefoot to himself forlornly. "It can't be anything I have eaten. I have nothing to worry about. Yet there is something wrong with me. I'm losing my appetite. Nothing tastes good any more. I want something, but I don't know what it is I want."

He tried to tell his troubles to his nearest neighbor, Timmy the Flying Squirrel, but Timmy was too busy to listen. When Peter Rabbit happened along, Whitefoot tried to tell him. But Peter himself was too happy and too eager to learn all the news in the Green Forest to listen. No one had any interest in Whitefoot's troubles. Every one was too busy with his own affairs.

So day by day Whitefoot the Wood Mouse grew more and more unhappy, and when the dusk of early evening came creeping through the Green Forest, he sat about and moped instead of running about and playing as he had been in the habit of doing. The beautiful song of Melody the Wood Thrush somehow filled him with sadness instead of with the joy he had always felt before. The very happiness of those about him seemed to make him more unhappy.

Once he almost decided to go hunt for another home, but somehow he couldn't get interested even in this. He did start out, but he had not gone far before he had forgotten all about what he had started for. Always he had loved to run about and climb and jump for the pure pleasure of it, but now he no longer did these things. He was unhappy, was Whitefoot. Yes, sir, he was unhappy; and for no cause at all so far as he could see.