The answer to 'why is my spider scratching sounds' is that the scratching or scraping noise is likely caused by the spider's movements and behaviors. Spiders use their legs and chelicerae (mouthparts) to move around, spin webs, and manipulate prey, and these movements can produce audible sounds, especially in quiet environments.
Some common reasons for spider scratching sounds include the spider moving across surfaces, building or repairing its web, or even molting (shedding its exoskeleton). These sounds are usually not a cause for concern and are a normal part of a spider's natural behaviors. However, if the sounds persist or seem excessive, it may be a sign of an infestation or other pest control issue, and you may want to consider calling a professional exterminator.