Stray Humans
Stray dogs are famous for peeing. But it isn't because they have a urinary bladder problem.
But they strategically use their pee to mark territories.
Humans, on the other hand, do have urinary bladder problems.
But it is rather tough to pee over the total 250,000 kilometers (155,000 miles) of national borders.
But here's the thing. In Psychology, there is a term called 'Epistemic Enactment' which describes how understanding emerges only through engagement with experience. To say, how will we know if we don't try?
There is nothing impossible to him who will try
— Alexander The Great Philosopher
If you are too inquisitive for your own good, you may point out that we already have better ways of marking territories and that pee might be redundant and even unseemly. I wholeheartedly disagree.
Envision this scenario:
Repeated signals from the center of the Milky Way could be aliens saying hello, new study claims | Live Science
If these aliens showed up for a greeting, this is what they will see of our planet.
A one-world island with a one-world ocean.
Is it not our responsibility to mark our territories properly? How will they know which is the strongest nation, and which is the weakest?
If they come at night, they may see that some areas are well lit while others are not. But they may mistake it for aesthetics. If they have binoculars, they may see that in some regions humans are very skinny with bones visible while in other regions they are rather broad. But they may ascribe it to fashion related diet preferences. They also may see quite a few people who are displaced from their homes due to some temporary conflict, but they may mistake it for wanderlust.
I think territories marked with an olfactory value may be able to effectively communicate the needful within the Earth system. Not only that but potential visitors from space will also get a better idea on who they ought to not mess with.