The Center for Disease Control recommends eliminating stagnant pools of water in your yard to avoid breeding grounds for mosquitoes, particularly those that can carry Zika, the West Nile Virus and other diseases. One of the most commonly overlooked places for stagnant water is a gutter with debris in it. While MasterShield’s openings are virtually microscopic, most gutter covers being marketed today have openings that mosquitoes can easily get through. Combined with the fact that they let debris in, allowing stagnant pools of water to form, these systems can be fertile breeding grounds for mosquitoes. Check your downspouts for a slow trickle of water that still occurs hours after a rainstorm and you likely have gutters that will attract breeding mosquitoes.