Bed bugs are difficult to spot, but there are several indicators of an infestation. Red, itchy bites often appear in clusters or a line on exposed skin, especially after sleeping. Small blood stains may be found on sheets, pillowcases, or mattresses, left behind after feeding. Dark spots, which are bed bug droppings, can appear on bedding, furniture, and even walls. Their tiny white eggs and shed skins are commonly found in mattress seams, furniture cracks, or carpets. In cases of a heavy infestation, a musty odor may be noticeable in affected areas. If any of these signs are present, professional treatment is necessary to prevent the infestation from worsening.