Mould is a common name used to describe numerous species of fungi – organisms responsible for decomposition in nature. In order to grow, they require a food source (organic material), moisture, oxygen and suitable conditions.
Mould is everywhere in the environment and many moulds produce spores that allow them to travel in air or water. Many species inhabit indoor environments preferring undisturbed humid and damp conditions. Museum collections, which are largely composed of organic materials, provide an opportunity for mould growth wherever object storage conditions are favourable to moulds.