Where are germs?

Everywhere. Although everyday surfaces may look clean, the chances are they are teeming with germs. At less than a thousandth of a millimetre in length, germs are invisible to the naked eye. Human skin carries hundreds of thousands of germs in a square centimetre, whilst saliva and the fluid in your nose contain millions of germs per gram. Dust is full of germ spores and soil and water may harbour millions of different species of germs.