Encasements are special devices that surround mattresses, box springs or pillows. They are used to trap bed bugs or eggs inside the encased item or to prevent bed bugs from entering.

Mattress encasements help the battle against bed bugs, but do not solve it. Encasements can trap existing harborages and eggs inside the mattress or box spring and prevent new bugs from taking up residence there. Bugs cannot bite you through the encasement, pre-adult bed bugs cannot reach reproductive maturity and unfed adults will not lay eggs until they feed. 

Benefits of bed bug encasements are as follows:

·         They can contain infestations residing inside your mattress or box springs, buying you time to replace your furniture.

·         Encasements can reduce the numbers of bed bugs that have access to you.

·         Encasements can prevent bed bugs from escaping, scattering and spreading from encased areas to other locations when using chemical treatments.

·         Mattresses and box springs are among the most likely hiding places and nesting zones for bed bugs. 

The effectiveness of encasements to resolve bed bug woes is limited. Bed bugs residing outside the mattress and box spring will still be able to access you and reproduce, so the next generation of bugs will simply reside outside the encasements. As a method of starving bed bugs, the mattress or box spring must be encased for a long time; bed bugs can live a long time without food if the conditions are ripe. Damage, tears, accidental unzipping or poor manufacturing can also limit the effectiveness of use. 

Encasements are not created equally. Numerous studies implicate design flaws in some encasements marketed for use against bed bugs. These include: fabric that does not prevent the insects from feeding through the encasement, zipper teeth with enough space to allow escape, zippers that easily pull back and allow escape, and fabric that easily tears.

According to Richard Cooper, an entomologist and designer of Protect-A-Bed encasements, this can create a false sense of security, actually worsening the infestation. His comparison research, presented to the Entomological Society of America in 2007, concluded that only the Protect-A-Bed encasement prevented bed bugs from escaping when the zipper was not fully closed. It is worth noting that his research puts him in an ethical dilemma; he was one of the designers of the Protect-A-Bed encasement and it is purported that he has financial interests in the product.

When deciding to use an encasement for bed bugs, be sure to look for a product specifically labeled for bed bugs. Some PCOs will advise against using encasements during treatment or following. Every PCO has different techniques for attacking bed bugs and the use of an encasement (especially an ineffective one) can complicate treatment. Follow his/her advice.