From The United States Code.
Apparently, if you find an island of bird crap, you have full fledged rights to export said crap (as fertilizer, I guess).
This must be on the books for some reason. Has anyone ever really had to have something like this spelled out in the frickin’ United States Code rather than a local (or closest continental) Court?
Tripler
I know the government has better things to do than shovel bird shit. :rolleyes:
Read the section on guano.
A long time ago there was some serious contention for guano supplies, as it was the major source of fertilizer.
In fact, it was so important that
Ain’t that some shit? 
According to this site guano was an “international commodity for almost 200 years”. The coastal Peruvians had been trading guano since before Inca rule.
It would seem that the US didn’t want to be held hostage by South American bird shit cartels and wanted to develop a domestic guano industry. Of course, guano lost its edge in thanks to our modern, better living through chemistry, world.
BTW, zoos often sell sell a wide assorment of animal excrement for people to mix into their gardens.
Sweet Jeesus, then the windshield of my truck is a veritable gold mine!
Airman Doors, I read that link. The worst part was that:
Jeez, not only are they shoveling shit, they’re living on it. :rolleyes:
Tripler
I had no idea shit was this hot!
Guano, or the lack of it, is one reason that Germany had to invest heavily in its nascent chemical industry in the years before WW1.
They had planned for a war and thought it likely that their access to ammonium nitrate, a precurser to certain explosives, would be either drastically reduced or stopped altogether by Britain.