The answer to 'why is my bed bug droppings' is that bed bug droppings are a common sign of a bed bug infestation in your home. Bed bugs feed on human blood and leave behind small, dark fecal spots as a result. These droppings are often the first visible indication that you may have a bed bug problem.
Bed bug droppings are typically found in areas where bed bugs hide, such as along the seams of mattresses, in cracks and crevices, and on furniture. The droppings appear as small, black or brown spots that may smear when wiped. In addition to the droppings, you may also notice other signs of bed bugs like shed skins, eggs, or the bugs themselves.