Carpets may look clean on the surface but underneath, there are countless of unwelcomed germs that have invaded your floor coverings. So, what causes bacteria growth? This is due to dirt, dust, sand and other small particles that have accumulated overtime. If these tiny debris are ignored, they can make your carpets look dirty and worn out as well as cause damage to the fabric. Not only that, harmful bacteria will grow and thrive underneath your floor coverings.