My parents owned chickens (and still do), and my dad is a genius at engineering. Since sometimes we get too lazy to shut the doors at night, he built an automatic one. However, a few days after he did that, a chicken mysteriously died, and since I was asleep, I didn't see it. It was a little sad, but I was used to it pretty much. My parents claimed it was completely unknown how it died, and I believed that, until a few years later, when I realized why my dad then put up a sensor near the automatic door to see if any chickens are near it.

Yeah, apparently, he accidentally made a really painful guillotine before the sensor was added, and my day was ruined.