If you are dealing with an ongoing case of bed bugs, it’s important to consider a few things when asking what causes bed bugs to come back.
1. Level of and length of infestation prior to treatment.
Bed bugs are wonderful at hitchhiking, and depending on the severity and length of infestation, the more chances you have at spreading bed bugs throughout the places you frequent.
There is a high possibility that you have contributed to infesting these places. If you go back, then it’s not hard for you to get a hitchhiker and re-infest your home again.
2. Quality of said treatment.
If you hired a company, or performed a treatment yourself and didn’t hit all the right areas, you may have killed all bed bugs, but eggs can be left behind and hatch up to a few weeks later.
3. Are you keeping up with post-treatment procedures?
Even if you have had the best treatment, depending on the severity of the infestation, it is not uncommon to have eggs buried deep in cracks. So as mentioned above, all bed bugs may have been killed but the eggs may have survived.
If everything is treated properly, you will still have places without a residual like bed skirts, linens, pillow cases etc. You need to frequently launder in high heat so no bed bugs gain a foothold to live long enough so they don’t outlast the chemical residuals that are in place.
4. Do you have reoccurring guests that visited before getting treated?
During infestations, it is not uncommon to pass said infestation along to your housemates. They may not know they are infested. Or they do, and do to the social stigma with bed bugs may not want to tell you.
Therefore, people can get a ping-pong effect of periods of no bed bug problems for a few months and back again, just between two homes.
Always make sure to let people know you have bed bugs so they may take proper measures so as not to bring them home.
5. Have you purchased new furniture after treatment, which is untreated?
This is pretty self-explanatory, however, I see it time and time again. People will buy a new bedroom set a month after treatment, none of this furniture has any residual. And just for some of the reasons stated above, you may bring them back home and you are back to square one.
Do not buy any new furniture until you have been all clear of any bed bugs for at least 3 months. Make sure you take proper measures when you come home to not re-infest.
For a more complete list of how to protect yourself from bed bugs, visit my other post Quickest way to get rid of bed bugs
6. Was a heat treatment the only type of treatment performed?
The way heat treatments are intended to work is by heating an entire room to 135 Fahrenheit. The problem with heat treatments is that when the room is heating up, the bed bugs will start running for cover.
If any bed bugs make it into the safety of a void, or deep crack where the heat is not penetrating, then the heat treatment is basically unsuccessful. I say this because there is no residual product and the bed bugs are free to infest your home again.