what is a problem we face due to the small size of microbes What is a problem we face due to the small size of microbes? Microbes are easily transferred between people by indirect and direct contact Microbes are large enough for us to see them microbes can\'t be controlled. What is the main reason why hand washing is no important? Solution Due to small size of microbes, they are easily transferred between people by indirect or direct contact. Microbes are invisible to unassisted eye because the size range of microbes are very less, about 1/10 of the typical human cell..