No, Mr. Bird, you can't sit here.
I was out in the back yard a week or so ago and just happened to see a bird perched happily on the pointy top of LilWeatherPi. I thought, "How nice," and went on about my business.
A couple of days ago I dropped LilWeatherPi to do some maintenance. I suddenly realized the bird resting on top of LilWeatherPi wasn't so nice after all.
Contrary to what many people believe, birds can control their poop. They just don't have much in the way of inhibition about where and when they let it rip. And their poop and pee comes out all mixed. Yuk! They typically will 'lighten their load' right before taking off, so where ever they are sitting normally gets a dose.
And that's what happened to poor LilWeatherPi.
I cut six inches of 1/4" steel cable and pulled out the center core braid. I then heated one end and melted it into the tip of the roof-like pointy cap. Then I unraveled it, making what sorta looks like some kind of antenna array. I've seen spikes used to dissuade birds before, so I thought this was worth a try.
Here's a little gallery:
Someone would really have to want to land there to even try that. That Works!
Details on LilWeatherPi are in this Dr.Gerg article and also on GitHub.