Attic insulation is one of the first casualties of rodent activity. Rats and mice use insulation for nesting, and their waste contaminates the material in ways that reduce its performance and create health concerns.

How Rodents Damage Insulation

Rodents burrow through blown-in and batt insulation, compressing it and creating tunnels. They urinate and leave droppings throughout, which soaks into the material and cannot be cleaned effectively.

Signs Your Insulation Is Compromised

• Visible droppings scattered across the insulation surface
• Flattened or displaced sections where nesting has occurred
• Strong odor, especially in warm weather
• Increased energy bills due to reduced insulation performance

Repair vs. Replacement

In most cases where rodent activity has been significant, full insulation removal and replacement is recommended. Spot repairs leave contaminated material in place, which continues to affect air quality and energy efficiency.

The Right Sequence

The proper approach is: remove rodents first, seal all entry points, decontaminate the space, remove old insulation, and then install new insulation. Skipping steps leads to recurring problems.