The very first suite I ever treated came with a complaint that there were bed bugs in the bed room door. At the time I could not understand why there would be bugs in such an odd location. I treated the door just to make the caretaker happy and soon discovered bugs pouring out of the top of the door!! I then decided to take the issue more seriously. As I gained experience I observed a number of occasions where the door was infested.
Interior doors are often very flimsy hollow core construction. Basically these doors are very thin paneling sandwiched onto cardboard or thin wood strips. As these doors age they often delaminate slightly in certain sections or are easily damaged due to their light construction. These imperfections are great hiding spots for bed bugs. Make sure you inspect the doors – especially if the tenant has been spraying raid or the infestation is substantial.