Three agricultural scientists were determined to discover how much a pig could eat before it just had to take a shit. To this end they procured a Yorkshire sow and pushed a large cork into her arse. After six weeks of force feeding, the sow was the size of the Goodyear airship and threatening to burst. Being humane types, the scientists agreed that the cork must now be removed.
No-one wished to volunteer for the job, however, so in true scientific tradition, they decided to train a monkey for the task and swiftly put a small gibbon through a crash course in cork-pulling. The day came and the pig was air-lifted out to the desert for safety's sake. Special equipment was set up to monitor the event. Picture the scene: In the middle of the desert, the pig. Behind the pig, the monkey. One mile behind him, the first scientists with a video camera. One mile behind that scientist are the other two scientists with a seismometer. Finally, the monkey reaches up and pulls out the cork. SPLAT!
When the massive geyser has subsided, the two scientists find themselves knee-deep in pigshit. Grabbing shovels they wade forward and dig out the first man who has been buried up to his neck. When they free him they find that he is laughing hysterically.
"What's so funny?" they ask.
"You should have seen the monkey trying to get the cork back in!"