They always look so elegant in documentaries about them, but how do they do a poo? Do they just let it trail out and swim away from it like a goldfish? Toilets are no good underwater.
And I've seen film of whole cities of merpeople. What about public health? I assume their cities are quite easy to find due to a vast expanse of merfolk floaters on the sea above. I did ask at work and it was suggested they probably have a special field just outside town for it.
Any experts in?