The Most Common Carrier of Communicable Diseases is (I) Ant, (II) Housefly, (III) Dragonfly, and (IV) Spider

Answer: Communicable disease refers to infectious diseases transmitted easily from the growth of pathogens. Thus, biological agents in humans and animals play an important role in communicating infections and illnesses. 

The answer is II; houseflies are the most common carriers of infectious diseases. The type of disease which could be easily spread from one to another is passed through houseflies. The most common types of contagious diseases are tuberculosis, malaria and AIDs. Hence, it is important to cleanse the home and surrounding areas to restrict entries of pathogens like a housefly. Cleaning and sanitisation will also limit the access to harmful bacteria that could cause varied types of disease.