carpet pad mold 2

https://carpetmoldremediationreport.halcyonledger.com/posts/effective-carpet-mold-remediation-what-works-and-what-doesn-t

Carpet pad mold often forms when moisture gets trapped beneath a rug or carpet, especially in basements or areas with high humidity. You might notice a musty smell or see dark spots if you lift the carpet's edge. Though it's unpleasant, catching it early means you can prevent it from spreading to the floor or carpet fibers above, so checking your padding once in a while helps keep the air in your home cleaner.