The answer to 'why is my mosquito scratching sounds' is that you are likely experiencing mosquito bites, which can cause itching and scratching. Mosquitoes feed on human blood, and when they bite, they inject a small amount of saliva that can cause an allergic reaction and itching. The scratching sounds are a result of you trying to relieve the itchiness of the mosquito bites.
Mosquito bites are common, especially during the warmer months when mosquitoes are more active. While the itching can be annoying, it's generally not a serious medical concern. However, if the scratching becomes excessive or leads to skin irritation or infection, it's best to consult a professional pest control technician or your healthcare provider.