Question

I’m a supervisor in a large data processing office. Several of my employees have complained about getting bitten at work although we can never find the bugs. We had a pest control company inspect the office. They said they couldn’t find anything but they sprayed the carpet. A week later, the biting has started again and people are getting mad. Can one of your people come out and spray something different?

Answer

We can have our technicians inspect the office, interview your employees, and leave monitor traps to check for pests. If you capture any pests, we can identify them. However, we won’t spray insecticide in the office unless we can confirm that there are pests present requiring control. Even when we do find pests, we like to use non-insecticidal (IPM) control methods first, when we can, and especially when people are present. Let me offer you this bit of encouraging information though: the feeling of being “bitten” is actually pretty common in certain office environments, and frequently insects or mites are not involved at all!

Mysterious bites from invisible bugs are most common in office environments with lots of paper, electrical equipment, fibers, and static. Conditions in an office can lead to skin irritation and “pinpricks” that feel, and even look, like insect bites. Here are some possible reasons for bites when no pests can be found:

Particles

High levels of static electricity can cause particles such as carpet fibers, paper splinters, or tiny pieces from air filters or fiberglass insulation to “jump” onto arms and legs causing irritation. Nylon carpet, electrical equipment, and low humidity increase static electricity levels. Complaints seem to increase in the fall when the heat comes on and the indoor air becomes markedly drier. Women who wear nylons are especially susceptible to static. When offices are sprayed with insecticide, workers get some relief from the “bites” because the water-based spray carries dust and particles down into the carpet and temporarily adds extra moisture to the air. Unfortunately, the relief is short-lived.

Indoor air pollutants

Modern buildings with closed ventilation systems may have periodic high levels of irritating chemicals such as formaldehyde, resins, and even insecticides. All can cause irritation or allergic reactions. An industrial hygienist can check your office space for air quality, chemicals, fibers, and other environmental conditions that could cause the feeling of bites. If environmental conditions turn out to be the cause of the bites, these can often be corrected by humidifying the air, thorough vacuuming or removal of carpet, and other measures.

Bell’s syndrome

Another thing that contributes to the feeling of being bitten in an office is a documented condition called Bell’s syndrome. This is basically “the power of suggestion,” transferred from employee to employee. When one person in a group feels an itch or biting sensation and begins to scratch or talk about it, others in the group soon follow suit. In most cases, the reassurance that there are no actual biting pests and that other conditions are the cause is enough to eliminate the symptoms.