Yes, bed bugs can be seen with the naked eye. Adult bed bugs are reddish- brown, flat, oval-shaped, and about the size of an apple seed (5-7 millimeters long). Young bed bugs, or nymphs, are smaller and lighter in color, sometimes nearly invisible due to their translucency, especially when unfed. Bed bugs hide during the day in tight crevices such as mattress seams, bed frames, furniture joints, and around baseboards, making them sometimes difficult to spot unless looked for carefully. Besides live bugs, signs of infestation include reddish or rust-colored stains on sheets or mattresses, tiny dark fecal spots, shed skins, and eggs about the size of a pinhead.
In summary, with close inspection, especially around sleeping areas, bed bugs can indeed be seen, but they often remain hidden due to their size, color, and preferred hiding spots.