RICHARD AMBROSE: Now it's time to zoom in to the microscopic world of the tiny creatures who inhabit our everyday lives.
JONNY PHILLIPS: There's nothing like collapsing into a freshly made bed at the end of a long, hard day. Crisp sheets, plump pillows, a warm, clean place where you can escape the grime and the grind of everyday existence.
RICHARD AMBROSE: Or can you? Just how clean is your bed? Well you might be horrified at the things you could sleep with.
JONNY PHILLIPS V/O: Meet Harry and his chums. Harry's a dust mite. Or, Dermatophagoides pteronyssinus. Try saying that ten times quickly. He's an ugly sucker. But fortunately you'll never come face to face with him. At just .2 to .3 of a millimetre long, it's virtually impossible to see him with the naked eye. And he'll certainly never see you because he hasn't got any eyes.
JONNY PHILLIPS: For the average bed, there can be anything from 100,000 to 2 million dust mites.
RICHARD AMBROSE: It's extraordinary. In a 2 year old pillow, the weight of it, 10 per cent of it could be dead mites and their excretions.
JONNY PHILLIPS: Eurr. And you know what they live on? Dead skin cells. If it wasn't for them we'd probably be wading around in dead skin.
RICHARD AMBROSE: They do a great job.
JONNY PHILLIPS: Yeah, good housekeepers. Bye Harry. Keep up the good work.