We made a small design mistake when we were installing our spa. It has a knife-edge border between the spa and the pool. It's like the Riviera for neighborhood doves, who like to dip stale bread in our water and poop on the tile.
![Owl](http://b.powerfulmojo.com/images/Owl.jpg)
1st Solution: Scary Fake Owl
Naturally, I wanted to prevent doves pooping in my pool. So I got this scary fake owl.
It didn't even work a little bit. If the doves noticed it all, it just helped them relax and move their bowels more freely.
2nd Solution: Scary Real Dog
When we were having some plumbing work done inside and outside our house at the same time, I parked a 90 pound dog inside the pool fence. I figured she would scare the doves away for at least a little while.
It didn't even work a little bit. She slept calmly in the shade and the doves seemed glad for the company.
3rd solution: A Slingshot
![Slingshot](http://b.powerfulmojo.com/images/slingshot.jpg)
I went on eBay and bought a "hunting slingshot." The slingshot is plenty powerful to destroy a dove, but there are 2 problems with that: 1) a missed shot would probably break a pool tile and 2) cleaning up dove carcasses is not much better than cleaning up dove poop.
So I got really light-weight ammo: Airsoft BBs weigh in at a fifth of a gram and they can't really do much damage. I also have some practice ammo. They're also lightweight and mostly harmless, but they bounce really far when they hit a hard surface.
This actually worked well. You don't even have to hit a dove. If a fast-moving projectile hits anywhere near one of them, they all fly off in a rush.
2nd Problem: Doves are quite stupid
It turns out you can hit doves with airsoft bbs over and over and over again, and they keep coming back. They just land on a power line above the alley and wait a minute. Then they all descend on the pool again.
I deem this problem unsolvable.