The answer to 'why is my drainage system pests' is that a poorly maintained or clogged drainage system can attract pests like mosquitoes, rodents, and insects. Clogged drains can create standing water, which provides a breeding ground for mosquitoes. Rodents may also be drawn to the moisture and nesting sites. Insects like ants, beetles, and flies can also be attracted to the debris and organic matter that accumulates in a poorly functioning drainage system.
To address this issue, it's important to regularly inspect and maintain your drainage system. This includes clearing out leaves, twigs, and other debris that can build up and cause blockages. You may also need to repair or replace damaged drainage pipes or components. In some cases, you may need to call a professional landscaper or plumber to diagnose and fix more complex drainage problems.