The answer to 'why is my pest scratching sounds' is that the scratching sounds are likely caused by a pest infestation in your home. Common pests that make scratching noises include rodents like mice or rats, as well as insects like woodworm or termites. These pests may be living in your walls, attic, or other hidden areas and will make audible scratching, scurrying, or gnawing sounds as they move around and build nests.
The scratching sounds may be accompanied by other signs of an infestation, such as droppings, chewed wires or wood, or visible pests. If you're hearing persistent scratching noises, it's best to inspect your home thoroughly and take action to identify and eliminate the pest problem. While some minor infestations may be treatable with DIY pest control methods, it's often best to call in a professional exterminator, especially for larger or more complex pest problems.