Rodents — Mice, Squirrels, and Chipmunks Like birds, rodents rely on the debris in gutters to craft their nests. However, squirrels, chipmunks, and mice present more of a hazard than birds because they have a way of finding their way indoors, especially during the colder months.

Dirt, dried leaves, twigs and other debris often make their way into your gutters due to wind and rain. Wind can bring small organic materials from your yard and neighboring houses into your gutters. The rain can also cause the dirt on your roof to travel into your gutter system.

Insects like mosquitoes, wasps, millipedes, and centipedes, among other creepy crawlers, are often found inside open-top gutter systems that aren't cleaned and maintained properly. Because debris like leaves, dirt, and rocks can get trapped in an open-top gutter system, clogs occur.

Sludge and silt in your gutters are often the result of different types of debris lumped together. In addition to algae and moss, they may also consist of many other kinds of organic materials that originate from the roof's surface.