Mould spores are the “seeds” of mould growth and are released into the atmosphere when mould grows. The spores are microscopic, easily breathed in and are potent allergens too. They are always in the air and just require a source of moisture (condensation) and food (dust) to start growing.
House dust mites live in your carpets, mattresses, pillows and soft furnishings. They are invisible to the naked eye. The mites themselves are not the problem – they won’t cause you any direct harm. The problem is their droppings. They are so small that they are easily breathed in and are allergy causing agents (allergens). Lots of warm moisture encourages them to breed – rapidly!