Size and Visibility
Bacteria is the largest family of organisms on the planet, with more species than all reptiles and insects put together. Which is precisely what they are. Reptiles and insects put together. Kind of mashed together randomly, not at all like Greek mythology. It is rumored that they take up more space on earth than all birds put together, but scientists are still puzzled as to how to assemble the birds, let alone take the integral of their moments of inertia, taking into account that birds are actually mostly hollow. Regardless, most experts agree that bacteria take up a lot of room. Which was surprising at first, because individual bacteria are microscopic. Until of course, the great Richard Dudu derived the Micro-Invisibility Theory using his toaster oven as a microwave gun.
 Micro-Invisibility Theory
Richard Dudu derived this theory when his microwave oven malfunctioned, splattering microscopic waves all over his kitchen, and thus revealing that many giant bacteria were crawling all over his walls. He thus concluded that bacteria are invisible to the naked eye, and can only be seen under the presence of microscopic waves. Scientists, who used to use microscopes for this procedure, now realize that really small bacteria are boring, and they ought to invest in hefty microwave guns for further and more exciting analysis of the larger species. Especially germs, which can often be as large as automobiles.
 Health Concerns
Bacteria have long been the concern of health nuts across the planet, with such fears as influenza, disease, and death. Bacteria have also been portrayed as blood-sucking, drooling, three-horned, infected mutant monsters by numerous leading companies in the cleaning agent industry, though evidence of all adjectives is yet to be proven. They do drool though. Profusely.
There is also great concern because bacteria occur in strange distributions. For instance, one must not worry about bacteria in a forest, whereas, on the sterile counter top of their kitchen, they are recommended to use Ultra-Kill 200% Soft and Cuddly Liquid Death Mango Super Cleaner from Klean Korporation Ltd. Also, it is perfectly safe to use a public washroom where twenty truck drivers recently held a conference, but in a home washroom, people are recommended to use another version of Klean Korporation's Top Cleaning Agent, this one of a more neon green color.
Health officials have been more than anxious to educate the public of the risks of bacteria, but so far they have only written several puzzling advertisements placed on city buses, since all of their funds were used to hire computer graphic engineers to animate the blood-sucking bacteria that these advertisements boast. They hope to one day have enough funds to buy their own youtube channel, where the public will decide it is hip and cool to buy more cleaning agents.