Mold has a musty, earthy smell that will be more noticeable in dry areas with poor air quality.
Indoor mold can often have a less obvious, but stronger almost pet-like odor when distributed throughout the home via clothes, upholstered furniture or carpets. This is because when mold spores are inhaled they are transported deep into the lungs where they are able to settle in the microscopic hairs coating your respiratory tract. These residuals can grow exponentially if given enough time, leading to an overwhelming amassing of mold and potential asthma flare ups due to allergy complications.