Microorganisms are all around us, they are also found inside our bodies. We can’t see them with our naked eyes. Some are good and some are bad. Some have shaped our lives for the better with applications in our daily lives, yet some torment us causing us to get sick. Micro-organisms fall within the following categories: viruses, bacteria, protista and fungi. Learn about the different kingdoms and the different ways they have affected our livelihoods.