The notion that insects only become resistant to chemical types of insecticides is unfortunately a myth.  Insects have shown resistance to all types of pesticides they just don’t boast about their accomplishments. It’s not that bed bugs and other insects are clever but rather nature seems to find ways to keep the little critters from being vanished from the world. 

Metabolic resistance is the preferred defense with insects. The bed bugs and other little critters that have received this gift from nature, detoxify the potent chemicals by utilizing their enzyme systems. They don’t even have to read a manual to accomplish the complicated task. Some biological, organic and inorganic pesticides can destroy the vast majority of a given insect population but as with their chemical cohorts they meet resistance by a  small group of stubborn insects.

Behavioral resistance has saved a small percentage of bed bugs and other insects from powerful insecticides. Some beg bugs see a red flag when confronted by a particular insecticide and may avoid death by staying away from it. 

Insects have developed resistance to heat, cold, starvation and other environmental factors. Some robust bed bugs can live for a year and a half without having a meal. Resistance has been offered by nature and unfortunately accepted by some bed bugs.