Checkout line of any major grocery store? Last one I picked up was made to hang on your keychain and I picked it up while waiting in line at Lowe’s.

On my grad-school campus, they had problems with a related species – starlings (which are supposedly edible but I don’ t know anyone – not even my backwoodsy officemate-at-the-time who used to regale us with stories of the different ways to prepare possum and why you have to cook groundhogs over an open fire [so the fat drains off properly] who would eat one). There were also pigeons (which I guess also are technically edible)

So the campus invested in some “bird control” technology: a large loudspeaker, mounted on the student union (which was unfortunately, next door to the library) that would play the distress-calls of birds about every 30 seconds during the daylight hours.

(I spent many, many hours in that library. At times, keeping a tally of how many times that @#@#!$ distress call went off).

The problem was, the tape was of some bird not native to the area (the ornithologist used to refer to the sound as “the squeezed seagull”), so after a few weeks, the birds acclimated to it. The dang thing STILL goes off, or at least it was the last time I was on campus for a visit.

I think lasers would have been much cooler. They would have had the added bonus of garage bands lining up to practice in the area so they could get their own laser light show.