Tomcat Rodent Block Expanding Foam Barrier fills gaps and cracks to keep mice from coming inside your home. This expanding foam is specially formulated to block mice providing a long-lasting airtight and water-resistant bond to most building materials. The foam can be trimmed sanded and painted if desired. Use in crevices inside and outside your home including the garage attic basement and foundation. Tomcat Rodent Block Expanding Foam Barrier is the pesticide-free way to keep mice out.