What is the primary method for correcting a house fly problem?

Implementing good sanitation practices is the primary method for correcting a house fly problem because effective sanitation can significantly reduce fly populations by eliminating their sources of food and breeding sites. House flies are attracted to decaying organic matter, including garbage, food scraps, and animal waste. By maintaining cleanliness in and around living spaces, such as regular disposal of waste, cleaning up spills and crumbs promptly, and ensuring that food is securely stored, the breeding environment for flies is disrupted.

In contrast, while using insecticides (the first option) may provide a temporary reduction in house fly numbers, it does not address the root cause of the problem. It can also pose risks to human health and the environment if not used properly. Trapping and removal (the third option) is a method that can help control existing fly populations, but it does not prevent future infestations unless combined with sanitation practices. Reducing outdoor waste areas (the fourth option) is certainly beneficial, but it is a broader strategy that may not fully encompass all potential breeding sites, especially within the home environment. Thus, good sanitation practices remain the most effective primary method for fly control.