One final point: no, Twain's punctuation is not correct; there are places where a comma should go. But I'm not going to fix that; for one, it's not my story, and two, he's a far better known writer than I am.
So, for your composition choice, should young Sam be repentent for what he did to Jim? Why doesn't he regret his decision, even years later? (Why is it so funny, and how does it show in his story?)
One afternoon I found the upper part of the window in Jim’s bedroom thickly cushioned with wasps. Jim always slept on the side of his bed that was against the window. I had what seemed to me a happy inspiration: I turned back the bedclothes and at cost of one or two stings, brushed the wasps down and collected a few hundred of them on the sheet on that side of the bed, then turned down the covers over them and made prisoners of them. I made a deep crease down the center of the bed to protect the front side from invasion by them, and then at night I offered to sleep with Jim. He was willing.
I made it a point to be in bed first to see if my side of it was still a safe place to rest in. It was. None of the wasps had passed the frontier. As soon as Jim was ready for bed I blew out the candle and let him climb in the dark. He was talking as usual but I couldn’t answer, because by anticipation I was suffocating with laughter, and although I gagged myself with a hatful of the sheet I was on the point of exploding all the time. Jim stretched himself out comfortably, still pleasantly chatting; then his talk began to break and become disjointed; separations intervened between his words and each separation was emphasized by a more or less sudden and violent twitch of his body, and I knew that the immigrants were getting in their work. I knew I ought to evince some sympathy, and ask what was the matter, but I couldn’t do it because I should laugh if I tried. Presently he stopped talking altogether—that is on the subject which he had been pursuing—and he said, “There is something in this bed.”
I knew it but held my peace.
He said, “There’s thousands of them.”
Then he said he was going to find out what it was. He reached down and began to explore. The wasps resented this intrusion and began to stab him all over and everywhere. The he said he had captured one of them and asked me to strike a light. I did it, and when he climbed out of bed his shirt was black with half-crushed wasps dangling by one hind leg, and in his two hands he held a dozen prisoners that were stinging and stabbing him with energy, but his grit was good and he held them fast. By the light of the candle he identified them and said, “Wasps!”
It was his last remark for the night. He added nothing to it. In silence he uncovered his side of the bed and, dozen by dozen, he removed the wasps to the floor and beat them to a pulp with the bootjack, with earnest and vindictive satisfaction, while I shook the bed with mute laughter—laughter which was not all a pleasure to me, for I had the sense that his silence was ominous. The work of extermination being finally completed, he blew out the light and returned to bed and seemed to compose himself to sleep—in fact he did lie stiller than anybody else could have done in the circumstances.
I remained awake as long as I could and did what I could to keep my laughter from shaking the bed and provoking suspicion, but even my fears could not keep me awake forever and I finally fell asleep and presently woke again—under persuasion of circumstances. Jim was kneeling on my chest and pounding me in the face with both fists. It hurt—but he was knocking all the restraints of my laughter loose; I could not contain it any longer and I laughed until all my body was exhausted, and my face, as I believed, battered to a pulp.
Jim never afterward referred to that episode, and I had better judgment than to do it myself, for he was a third longer than I was, although not any wider.
I played many practical jokes upon him but they were all cruel and all barren of wit. Any brainless swindler could have invented them. When a person of mature age perpetrates a practical joke it is fair evidence, I think, that he is weak in the head and hasn’t enough heart to signify.