One of the funniest stories Mark Twain ever wrote..

Is in Roughing It. Mark Twain's brother was an officer in the Nevada Territory, and Mark Twain went with him and hooked up with some surveyors for the railroad:

"Romantic adventure" could go no further. They surveyed very slowly, very deliberately, very carefully. They returned every night during the first week, dusty, footsore, tired, and hungry, but very jolly. They brought in great store of prodigious hairy spiders--tarantulas--and imprisoned them in covered tumblers up stairs in the "ranch." After the first week, they had to camp on the field, for they were getting well eastward. They made a good many inquiries as to the location of that indefinite "certain point," but got no information. At last, to a peculiarly urgent inquiry of "How far eastward?" Governor Nye telegraphed back: "To the Atlantic Ocean, blast you!--and then bridge it and go on!" This brought back the dusty toilers, who sent in a report and ceased from their labors. The Governor was always comfortable about it; he said Mrs. O'Flannigan would hold him for the Brigade's board anyhow, and he intended to get what entertainment he could out of the boys; he said, with his old-time pleasant twinkle, that he meant to survey them into Utah and then telegraph Brigham to hang them for trespass!

The surveyors brought back more tarantulas with them, and so we had quite a menagerie arranged along the shelves of the room. Some of these spiders could straddle over a common saucer with their hairy, muscular legs, and when their feelings were hurt, or their dignity offended, they were the wickedest-looking desperadoes the animal world can furnish. If their glass prison-houses were touched ever so lightly they were up and spoiling for a fight in a minute. Starchy?--proud? Indeed, they would take up a straw and pick their teeth like a member of Congress.

There was as usual a furious "zephyr" blowing the first night of the brigade's return, and about midnight the roof of an adjoining stable blew off, and a corner of it came crashing through the side of our ranch. There was a simultaneous awakening, and a tumultuous muster of the brigade in the dark, and a general tumbling and sprawling over each other in the narrow aisle between the bedrows. In the midst of the turmoil, Bob H---- sprung up out of a sound sleep, and knocked down a shelf with his head. Instantly he shouted:

"Turn out, boys--the tarantulas is loose!"

No warning ever sounded so dreadful. Nobody tried, any longer, to leave the room, lest he might step on a tarantula. Every man groped for a trunk or a bed, and jumped on it. Then followed the strangest silence--a silence of grisly suspense it was, too--waiting, expectancy, fear. It was as dark as pitch, and one had to imagine the spectacle of those fourteen scant-clad men roosting gingerly on trunks and beds, for not a thing could be seen. Then came occasional little interruptions of the silence, and one could recognize a man and tell his locality by his voice, or locate any other sound a sufferer made by his gropings or changes of position. The occasional voices were not given to much speaking--you simply heard a gentle ejaculation of "Ow!" followed by a solid thump, and you knew the gentleman had felt a hairy blanket or something touch his bare skin and had skipped from a bed to the floor. Another silence. Presently you would hear a gasping voice say: "Su--su--something's crawling up the back of my neck!" Every now and then you could hear a little subdued scramble and a sorrowful "O Lord!" and then you knew that somebody was getting away from something he took for a tarantula, and not losing any time about it, either. Directly a voice in the corner rang out wild and clear: "I've got him! I've got him!" [Pause, and probable change of circumstances.] "No, he's got me! Oh, ain't they never going to fetch a lantern!" The lantern came at that moment, in the hands of Mrs. O'Flannigan, whose anxiety to know the amount of damage done by the assaulting roof had not prevented her waiting a judicious interval, after getting out of bed and lighting up, to see if the wind was done, now, up stairs, or had a larger contract. The landscape presented when the lantern flashed into the room was picturesque, and might have been funny to some people, but was not to us. Although we were perched so strangely upon boxes, trunks and beds, and so strangely attired, too, we were too earnestly distressed and too genuinely miserable to see any fun about it, and there was not the semblance of a smile anywhere visible. I know I am not capable of suffering more than I did during those few minutes of suspense in the dark, surrounded by those creeping, bloody-minded tarantulas. I had skipped from bed to bed and from box to box in a cold agony, and every time I touched anything that was furzy I fancied I felt the fangs. I had rather go to war than live that episode over again. Nobody was hurt. The man who thought a tarantula had "got him" was mistaken--only a crack in a box had caught his finger. Not one of those escaped tarantulas was ever seen again. There were ten or twelve of them. We took candles and hunted the place high and low for them, but with no success. Did we go back to bed then? We did nothing of the kind. Money could not have persuaded us to do it. We sat up the rest of the night playing cribbage and keeping a sharp lookout for the enemy.

http://www.mtwain.com/Roughing_It/22.html/spiders