Although flies are known as annoying insects, they also have a huge affect on the human society. Because they lay their eggs in feces and they eat garbage, flies carry pathogens which are harmful to humans and animals. By exposing themselves to the feces and garbage, they risk spreading pathogens to humans and animals through vomiting and defecating on our food. On the website Featured Creatures by The University of Florida, the article on the house fly discusses disease transmission. It states, "Among the pathogens commonly transmitted by house flies are Salmonella, Shigella, Campylobacter, Escherichia, Enterococcus, Chlamydia, and many other species that cause disease." These pathogens are very threatening to humans and can cause very serious sicknesses.
Not only do flies transmit diseases, but they have a very large population around the world. There are many types of flies and even the amount of house flies may be too much for the world to handle. Flies lay thousands of eggs at one time. They only have a life span of about a couple of days, but within that time, they have the ability to transmit multiple diseases. If the population of flies increases, the earth may have a problem. The use of chemicals, traps, etc. can be used to to control them, but controlling the population can only go so far. Lets hope that increase doesn't happen any time soon!