Unfortunately, there's no way for me to confirm that these pictures are of bed bug fecal matter. The last picture probably isn't, as bed bug poop doesn't come out that solidly. They tend to streak because the bed bugs poop while moving. They're classy like that. Those streaks could be a number of things: ink, charcoal, other pests.
Bed bug fecal matter is dark in color made up of digested blood from their host. Bed bug feces is smooth to the touch unlike roach feces, which is more granular in feel. The fecal matter is easy to smear and can quickly stain mattresses, sheets, drapes, furniture, sofas and chairs. Below are some bed bug feces pictures.
When these bugs are infesting a mattress, black patches of feces can be found on the corners or along the seams. If they have infested a piece of furniture, black residue can be found on stitching and in the creases or folds.
Bed bugs can also hide on almost any other type of surface including metal and plastic. The photo on the right below shows how a number of bed bugs found harborage together inside a the head of screw. All of the photos of bugs above are also from Lou Sorkin's vast collection of bed bug photos. Bed Bug Cast Skins/Shells
Bed Bug Behavior and Habit. Understanding the behavior of bed bugs (how they eat, live, and reproduce) will help you to find an infestation before it becomes established and to monitor for the presence of bed bugs after your home has been treated.
Bed bug feces ("poop") leave dark stains that look like a felt tip marker stain. The stain will often "bleed" into the fabric and look as if you went to bed with an open sharpie pen. When you inspect for bed bugs , you may find stains like these on your pillow case or sheets or on the mattress itself.