How did he feel during his first fight

At first he felt frightened; then he was inexplicably happy.

"They made noises, and at first he was frightened at them. Then he perceived that they were very little, and he became bolder. They moved. He placed his paw on one, and its movements were accelerated. This was a source of enjoyment to him. He smelled it. He picked it up in his mouth. It struggled and tickled his tongue. At the same time he was made aware of a sensation of hunger. His jaws closed together. There was a crunching of fragile bones, and warm blood ran in his mouth. The taste of it was good. This was meat, the same as his mother gave him, only it was alive between his teeth and therefore better. So he ate the ptarmigan. Nor did he stop till he had devoured the whole brood. Then he licked his chops in quite the same way his mother did, and began to crawl out of the bush.

He encountered a feathered whirlwind. He was confused and blinded by the rush of it and the beat of angry wings. He hid his head between his paws and yelped. The blows increased. The mother-ptarmigan was in a fury. Then he became angry. He rose up, snarling, striking out with his paws. He sank his tiny teeth into one of the wings and pulled and tugged sturdily. The ptarmigan struggled against him, showering blows upon him with her free wing. It was his first battle. He was elated. He forgot all about the unknown. He no longer was afraid of anything. He was fighting, tearing at a live thing that was striking at him. Also, this live thing was meat. The lust to kill was on him. He had just destroyed little live things. He would now destroy a big live thing. He was too busy and happy to know that he was happy. He was thrilling and exulting in ways new to him and greater to him than any he had known before."