use Perl

Several years ago, while wandering through the local Fry's Electronics, I started noticing a periodic, irritating electronic chirping noise. Birds used to get into this Fry's, so I figured it was some sort of attempt at repelling birds. Over the years, it got worse, to the point of being really annoying. It seemed to happen all over the store, at random intervals.

I was in a department store last week, and noticed the same chirping coming out of the Men's department. This seemed odd, so I tried tracking the noise down (a tricky endeavor, since the sound echoed, and seemed to move around the store). Eventually, I was standing next to a rack of leather jackets when one of them chirped. The culprit was an anti-theft tag. I asked an employee, and they confired that the tags did that when they ran low on charge, but that "we get use to the noise, and hardly notice them anymore."

There are probably several lessons here about designing systems that need to raise periodic alarms.