Which of the following practices can reduce mosquito breeding sites?

The practice that effectively reduces mosquito breeding sites is clearing standing water. Mosquitoes require stagnant water for their reproduction, as females lay their eggs in such environments. By removing or regularly emptying containers, bird baths, tree holes, and other sources of standing water, you significantly diminish the potential habitats where mosquitoes can breed.

In contrast, overwatering gardens can actually create additional standing water, increasing the likelihood of mosquito breeding. Leaving containers outdoors, especially those that can collect rainwater, can also become breeding grounds if not properly managed. Eliminating all wildlife is not a viable or effective measure, as many wildlife species play essential roles in the ecosystem and also can contribute to pest control in various ways. Therefore, clearing standing water is the most effective practice in managing and reducing mosquito breeding sites.