Can mold spread whan it's in a ziplock bag?

Mold can potentially spread even in a ziplock bag if there is moisture present, as mold spores can remain viable in contained environments. If the conditions inside the bag are suitable—warmth and humidity—mold can grow and spread. However, if the bag is kept dry and sealed properly, the growth may be limited. It's important to inspect food or items for mold before sealing them in bags.