SCENES FROM A MATTRESS
In this video you see in action the instinctive preferences of BedBugs for sunken surfaces. This is a scene of tuft of a mattress where the BedBug is crawling. Along the way you would notice white shiny eggs and black extruding excrement markings.
The BedBug is comfortable being in the sunken space. It is obvious as I am not able to nudge it with my finger on first few attempts. My finger was not able to come into contact with the BedBug as it was in the sunken space just next to the mattress tuft. After the nudging attempt is successful, the BedBug feels threatened and moves along the tufts rather than the open flat surface further away, but finally move perpendicular to the other side of the mattress.