Date of this Version
House mice (Mus musculus) were introduced into 20, 4-inch thick insulated panels and provided unlimited food and water for six months. Mouse populations increased 3-to 4-fold inside the insulated panels. Aluminum foil vapor barriers were severely damaged by mice and in all cases, reduced to less than half of their original mass. All of the insulation materials tested (insulation board, fiberglass batt, rockwool, beadboard, and vermiculite) sustained significant levels of damage as measured by increased thermal conductance. Researchers have yet to discover an insulative material that is not susceptible to house mouse damage. Producers should use construction techniques that exclude house mice and other rodents from insulated walls. In addition, house mouse populations in and around buildings should be controlled to minimize economic damage.