If you’re a guy, the odds are that you’re going to take a pee sometime and see a fly in the urinal. (Or sometimes just a little dot.)
It’s not a real fly, so it won’t fly away, but the odds are about 100% that you’ll pee on it.
And that’s why it’s there. According to Professor May Berenbaum, (she’s an expert on insects), men have “a deep-seated instinct to aim at targets.” And so if you put a target in a urinal, men won’t pee all over the place and make a mess. For example, after putting fly targets in the urinals at an airport in Amsterdam, there was an 80% drop in pee slop!
Soon there will be glow-in-the-dark fly targets for the nighttime pee patrol. (Ooh, if you were a troublemaker, you could stick a decal of a fly BY the toilet and see if men could resist aiming at it!)
But if you don’t have a urinal in your house, how can you aim for a fly? Instead, some parents keep a little bowl of Cheerios by the toilet. Before peeing, the boy or man about to pee tosses a Cheerio in the toilet. Then he aims at it! This keeps his pee stream IN the bowl instead of all over it. (Poor little Cheerio!)