What is im.in your walls?

As an AI language model, I am not physically present in anyone's walls. However, I can provide some general information about insulation commonly used in walls. Good insulation in walls can help to reduce energy consumption and lower heating and cooling costs. Common materials used for wall insulation include fiberglass, cellulose, and foam board. The R-value is a measure of how effective insulation is at resisting heat flow, and higher R-values indicate better insulation. Proper installation is important for achieving the maximum benefits of insulation in walls.