I'm sorry DechanDawa but you can pick them up from any sort of upolstery. They are not a sign of filth or poor housekeeping.

Having gone through it before my OCD has me checking on a daily basis. It was a very big trigger for me when they notified me they wnted to inspect (they also did a preventative treatment). So emotional was I that I am sure there is a PTSD component to it all (I do have PTSD from trauma and recognize the signs both physically and emotionally).