Look closely at these photos. Bed bugs look quite different depending on their life stage and whether they have fed or not.

Sean the PCO suggested putting a disposable hand warmer in the center of the glue trap as this would release CO2 and heat, thereby more likely attracting bed bugs.

We do have a FAQ now on catching a sample.

As the FAQs indicate, I do not recommend doing your own pest control, so I am glad you’re not going that route.

hopelessnomo’s advice is correct in that getting a professional to treat without evidence–even when they are willing–is problematic.

I can think of one person who treated herself for months before offering her DIY pesticides as a gift to others on the yahoo group, when eventually became clear she had folliculitis. And others with bed bugs encouraged her to spring into action and self-treat, and she wasted months of her life and lots of money.

I can think of others who were treated without definite evidence, one of whom paid a PCO who would treat in this circumstance, and she never ever was sure she actually had bed bugs, though at the time, she was “sure.”

It’s worth getting doctors to rule out everything medical, and it’s worth remembering that they cannot diagnose bed bug bites by appearance. That doesn’t mean you don’t have bed bugs, but I would agree with those suggesting you find concrete evidence before treating.

Another thing to remember is that you can actually have a delay from hours to days (as long as 9 days, we’re told) before bite marks and itching appear (if they do: we’re told as many as 50% of people have no reaction to bites).

Most of us seem to get them within 24 hours, though few actually see themselves bitten and know for sure. In your case, this delay can mean you were not even bitten at home. It’s possible that you were bitten in someone else’s home or another place you have been on those occasions. Keeping a journal of when new bites appear may help.

The link to NotSoSnug’s methodology describes something painstaking but which may bear fruit.

It’s impossible ethically to suggest that you treat with pesticides without evidence.

If you have bedbugs, there are fecal traces somewhere in your home that you are not finding.

They can hide in the tiniest places and you may have to take the painstaking route of examining everything. Start at the head of your bed and proceed from there. What I meant by taking things apart is that you have to be prepared to, for example, take down a picture frame and open it from the back and examine every centimeter on all sides and between the glass and the print…

When you examine a nightstand, you have to take out the drawer if it has one and look very closely at the back, the underside, and turn over the piece of furniture and examine it from all sides. There are many, many other places to look. You should check out the many resources, photographs and videos linked on the sidebar here. They should help.

You should be able to find at least fecal traces somewhere.

There was someone here who found a harborage inside a smoke detector that everyone, including the PCO, had overlooked.

The problem with treating without evidence is that, if you are wrong, the problem will not go away but by then you will be so invested in having bedbugs — bedbugs that can’t be killed at that — that you will be less likely to look for alternative explanations.

If you can afford it, a dog might be a solution here.

Also, while you may think it was the holiday guest, what if there is another source? What if the neighbors have bedbugs? Have you talked to them? Many people have bedbugs and don’t know it (because they are not attuned to the signs and/or are not allergic), or have bedbugs and are getting treated but have not been advised to inform their neighbors, or the landlord, whose responsibility this is, refuses to have the adjacent apartments inspected.

What I’d like to add is a comment and plea for PCOs.

It is crystal clear to me that PCOs should focus on detection because timing is crucial when it comes to bed bugs. In the Bed Bug Handbook it clearly states how difficult and nearly impossible it is to detect low-level populations by visual inspection (p. 98). Structural problems, like old floorboards with innumerable cracks, as in my apt, make the job of finding a bug impossible. Getting an inspection with a trained dog seems the only option (and in fact I am getting one).

My plea for PCOs is that in difficult situations in which the population may be low, they should either develop methods for getting that bug out of the crack or offer a trained dog, instead of simply telling you that with no evidence they won’t treat. Waiting means allowing the population to grow and the infestation to get much more difficult and troublesome to eliminate.