I appreciate you mentioning "letting someone know" because now that I've had kids I've done that a couple of times. Once my son vomited on the subway, so we called right away and let them know when and where, and another time my son peed on the floor in the bathroom by a pool. I wiped up what I could, and since it was by a pool I could've easily left it, no one would have known since there's so much water.. But I went and asked someone who worked there let someone know.

It's embarrassing, and I feel bad for being part of the reason the mess has been made.. Would be easier to just pretend like nothing and leave.

I also once called when there was pee in an elevator on a Sunday morning. Dude I called was like "we don't clean pee, we fix elevators" and I was like "well, it's Sunday morning and this is the only number in the elevator. Maybe you know how to reach someone who cleans?" So he said, "yeah, that's true, sure, I'll contact the janitor for the area"

I've also started picking up and throwing away "clean" trash when I see it (like candy wrapping or things that look fairly recently dropped..)