Brain teaser 4 We use faeces (dung) as a fertilizer to help our crops grow. So why worry about keeping it out of water and food? 1| 2|3|4|5| Next >>

The problem is that untreated faeces often contains viruses, bacteria and parasites that can make you ill. In fact, one gram of human faeces can contain:

• 10,000 viruses
• 1,000,000 bacteria
• 1,000 parasites
• 100 parasite eggs

Next >>