The world's greatest number of living things simply cannot be seen. They are microbes. They are vital to our lives, helping our guts digest food, for example. You can see an example of microbes at work in the video on cheese-making below.

People mostly only get to know about microbes when infections occur, and most of the adverts you see suggest microbes are terrible and need killing. That is completely wrong. Like all living things, microbes are part of the web of life. All larger living things depend on them, and all living things have ways of keeping them in balance. Problems only occur if the balance goes wrong, but even then living things have a way of dealing with them. In our bodies it is the white cells in the blood. They are microbe-destroyers, but they only get triggered into action when the body tells them to, for example, if we get a temperature.

Of course, sometimes, microbes get the upper hand, and that is why we use antibiotics. But antibiotics have a habit of killing off more than the dangerous microbes, and they leave us open to more attacks until our white cells and other parts of our defences (the immune system) get back up to speed. So antibiotics are a last resort. They also only work on bacteria. They have NO effect on viruses, and illnesses like cold and flu are due to viruses.

Immunisation is a better way to deal with some viruses. A flu jab is an example. That boosts the body's natural defences.