It is not recommended to microwave food that a fly has landed on as a method of sanitizing it. Microwaving food does kill many types of bacteria and other microorganisms due to the heat generated, but it may not effectively eliminate all potential pathogens or toxins that could be present on the food.
When a fly lands on food, it can transfer bacteria and other contaminants from its body or legs onto the surface. Microwaving the food may not necessarily kill all the bacteria or remove any toxins that the fly might have left behind. Additionally, microwaving may not distribute heat evenly throughout the food, which can lead to uneven cooking and potential food safety issues.
To ensure the safety of your food, it's generally best to discard any food that has come into contact with flies or other pests. It's important to store food properly, cover it when not in use, and maintain a clean environment to prevent contamination. If you have concerns about food safety or sanitation, it's advisable to consult with a food safety expert or follow the guidelines provided by your local health authorities.