06 May How do starving bed bugs react to a nearby host?

 

Over the years I have done a number of experiments on starving bed bugs. When I walk into the experiment room during the day the bugs are usually inactive. You might note the odd bug or two moving about but the majority are stationary. If you sit and watch them (from about 2 feet away) for 10 or 15 minutes the bugs slowly start becoming more active. The bugs also tend to congregate as close as possible to where I am sitting. Some bugs will actually climb the experimental apparatus nearest to me and appear to look at me. My last experiment confirmed this again. I starved the bugs for 18 days, came into the experiment room, waited a few minutes, and noted the activity levels ramp up.

As such the circadian rhythm of the starving bed bug appears to be overridden by the presence of a host. This is important in public settings. When bed bugs are inadvertently dropped in public areas their environment is not very conducive to feeding. But if they starve long enough and a host is nearby the bugs will be stimulated and find you. The same pattern can be noted when a jar of bed bugs is heated with the warmth of human hands. The bugs become stimulated by the heat cue and begin searching.

How would this manifest itself practically? Two stories are applicable here. I was standing beside an infested couch in a suite with the landlord. The suite had two room mates with one room mate gone travelling. The traveller typically slept on the couch leaving the bugs on the couch hungry. After ten minutes of talking the landlord noted bugs climbing on his sandals which precipitated a frantic chicken dance.

A second story involves my questioning the local librarian about bed bugs. A bed bug was discovered climbing the leg of a librarian as she sat in her chair. I suspect a bug was dropped in the library, became starved, and attacked the nearest host which happened to be a librarian. A search of the library by the exterminator revealed precious little evidence of other bugs.

These observations have caused me to respect the bed bug particularly in empty infested suites. I am not afraid to walk through the suite but will purposely avoid standing still for more than a few minutes in one spot. It takes a few minutes for the bugs to become stimulated and again some time to find you. Sitting in an empty infested suite for an hour is a definite no no.

A suite that is occupied is typically less dangerous because the bugs are fed and less likely to attack you. To minimize risk further simply avoid standing beside any potential sleeping surface. Speaking with an infested tenant by the door for a few minutes is not very dangerous and a chicken dance is not required. But don’t sit on the couch!!!