After Bed Bug Treatment: Why Treatments Fail, and the Two-Week Rule

The four reasons (MSU Extension)

“There are several reasons why a treatment may not be effective: All sources of the bed bugs were not identified during the inspection phase. All sources of bed bugs were not treated. Ineffective insecticides were used or there was insufficient contact time if heat was used. Re-introduction of infested items.”

The first three are why we inspect adjacent units, probe the cold spots and time the hold from the coldest sensor. The fourth is the one to watch after we leave.

If you had a chemical program

“If the PMP used conventional treatment, there may be some surviving eggs that will hatch. ... A conventional chemical treatment program will usually require at least one follow-up treatment two weeks later.” That visit is scheduled when you book, not when you call back.

If you had heat

Eggs are dead; the residual dust in the voids handles anything that walked in from a wall. We re-check at two weeks anyway, because the manual’s failure mode for heat is a location that never reached temperature, and the only way to know is to look.

First two weeks

• “Encasements should be put on mattresses and box springs” (MSU) — and left on.
• Keep bagged clean items sealed until the re-check.
• Interceptor cups under bed legs; check them every few days.
• No second-hand upholstered furniture. Inspect luggage after travel; the dryer for 30 minutes handles clothes.