The answer to 'silverfish scratching sounds' is that these noises are typically caused by silverfish, a common household pest. Silverfish are small, silver-gray insects that feed on carbohydrates and can often be heard scurrying and scratching inside walls, cabinets, and other areas of the home.
Silverfish scratching sounds are a sign of their presence and can indicate an infestation. In addition to the noises, you may also notice signs of silverfish damage, such as holes or stains in paper, fabrics, or other materials. While silverfish are generally harmless to humans, they can cause damage to household items and may be a nuisance.