What might a musty smell indicate Rat mice cockroaches or flies?

A musty smell often indicates the presence of mold or mildew, which can be associated with dampness and poor ventilation. While it’s not directly linked to rats, mice, cockroaches, or flies, these pests may thrive in environments that are humid or decaying, potentially contributing to the smell. Additionally, the droppings or dead bodies of these pests can also produce a musty odor. Therefore, addressing moisture issues and pest control measures is crucial.