We know that a million and a half children die a year from diarrhea and a lot of it is because of open defecation.

You start to talk to them about why open defecation is something that shouldn't be done in the village, and they agree to that.

And that's because there is no clean water to drink, or in countries like India, people don't know that they need to soap their hands before defecation.

Improved sanitation and hygiene practices could be encouraged by setting targets and providing incentives to communities to meet them (as with the zero open defecation initiative in India).

These approaches will not depend on household subsidies, but rather will encourage community based approaches for total sanitation' that seek to eliminate the practice of open defecation, while enabling the poorest, including female headed households, to build their toilets without undue duress.

Hygiene promotion that focuses on key household practices (washing hands with soap after defecation and before handling food, and the safe disposal of children's faeces) is also an effective way to prevent diarrhoea, especially among young children, who spend most of their time at home.

So, literally, a few minutes before that, I downloaded this scientific paper about calculations on avian defecation, which is really quite interesting, because it turns out you can model this as something called Poiseuille flow, and you can learn an awful lot about the physics of the avian rectum.