The answer to 'why is my mosquito droppings' is that you likely do not have mosquito droppings. Mosquitoes do not produce droppings in the traditional sense. Instead, they leave behind small spots of blood or other liquids after feeding on humans or animals. These spots are not actually droppings, but rather the remnants of the mosquito's feeding process.
If you are seeing small dark spots or splatter marks in your home, it is more likely that these are caused by other pests, such as flies, spiders, or even rodents. Mosquitoes do not leave behind visible droppings like some other insects and pests. If you are concerned about a potential pest problem, it's best to call a professional pest control technician to inspect your home and identify the source of the issue.