After bats have been evicted from your Frederick home, the attic should be cleaned. The entire area must be properly sanitized. Their feces or guano most likely contains Histoplasma Capsulatum. This is a fungus that leads to lung disease in people. This can occur when there is enough buildup that the fungus enters the air. It can also happen during clean up if not done safely. The risk is not super high but worth avoiding. Especially in homes that have elderly or very young people. The risk is worse for those with weak immune systems.
Bats can also introduce mites into the home. They are similar to bed bugs. The final issue which must be addressed during cleanup is the urine and guano. Their urine and dropping can seep into drywall, insulation, and particle board.
Often homeowners will try to spray the area to decontaminate it. This is not the first step. All droppings must be safely removed. All urine or guano contaminated insulation must also be removed. It can be easy to identify insulation ruined by droppings, but it can be more difficult to find insulation contaminated by urine. This is especially true if it has dried. It is recommended to call in professionals who have the proper equipment to handle contaminated insulation. Many homeowners may attempt this job themselves with plastic bags and shovels. They will often miss some ruined insulation or risk disease as they shift the contaminated insulation. Often professionals will use an insulation vacuum meant for this job.
Once all the insulation has been removed, the the area must be decontaminated. This will kill any mites and disease left on the surface under the damaged insulation. After the area is safe a deodorization is recommended. This is to remove any lingering smells from the urine and guano. Finally after all this, then new insulation can be installed. This can be blown-in or fiberglass. Often the owner can take this opportunity to raise the R value of the insulation. This can provide better energy efficiency to the home. Depending on how long the removed insulation had been in place can help determine how much more should be installed. The older the insulation probably means less R value was used to begin with so even doubling the amount can be an option.
