Your student’s may giggle at this infographic, but “no invention has saved more lives than a toilet. Billions still lack one. Lack of sanitation is the world’s biggest cause of infection. All of this, entirely preventable.” This quote is entirely true and taken from visual.ly. Toilets are private today, but are extremely important.
How have ancient civilizations used the toilet? Is this a modern invention, or did ancient Rome have them? Rome actually did. Forgive me if I am wrong about the specifics (the location), but I seem to remember hearing about a series of seats outside of an ancient coliseum with holes in them, assumed to be toilets. This shows that an ancient civilization recognized the importance of sanitation (although not our more modern concept of toilet modesty).
What are other aspects of bathrooms that may be useful when traveling? When I was in Germany just before the Euro was introduced, I remember there being restrooms in train stations, but having to pay a small amount (I believe it was 5 Pfennig, about 3 cents) to use it. Because it cost a small amount, these public restrooms were very clean. I have also seen pictures of toilets in Japan, and will have to explore how to use them in more detail before I travel there.