Harris Pyrethroid-Resistant Bed Bug Killer is the most effective at killing bed bugs of all types and their eggs. There are small pockets of pyrethroid resistant strains of bed bugs in located in some cities in the US. For those strains, tough pyrethroid resistant insecticides are needed to effectively eliminate the bed bug colony. We recommend using this product in combination with our bed bug aerosol and diatomaceous earth powder. EPA registered in all 50 states for use in homes, apartments and residences. Not for use on children or pets.