Most people are familiar with the extensive destruction that termites can cause to wooden structures. Termites can also damage structural wood in steel and concrete buildings, such as trim or molding, paneling, furring strips, or door and window frames. Stored files, stacked books, or any other cellulose-based material (such as fiberboard sheathing or insulation panels) may also be attacked.
Most termite problems in large buildings involve subterranean colonies that persist for years on buried scrap wood and constantly explore upwards for new sources of food. These colonies are often a nuisance not because of the actual damage they cause, but because large numbers of winged "swarmers" periodically find their way into occupied space. Although extremely disruptive, swarmers are harmless, cannot bite or carry disease and cannot damage interior wood. Swarming termites should be controlled with a vacuum rather than a space spray, but spraying may be unavoidable in rare circumstances. The presence of swarming termites should be followed with a termite inspection by a professional pest control company.
Many types of ants produce winged queens and males at certain times of the year. Large numbers of these "swarmers" may pour out of crevices into a room, even in locations that never had a problem with crawling ants. Swarming ant reproductives are sometimes confused with termite swarmers (Appendix II). Swarming ants can severely disrupt operations and often result in occupant demands for spraying. In cases where the ants are relatively concentrated (such as at windows), the recommended procedure is to vacuum them up and dispose of the contents in an outdoor trash bin.
However, in some cases, control with an insecticide may be the only practical response. Winged ants emerging inside a building usually die or disperse quickly, so spraying tends to be of little value if not done immediately. Rooms should be unoccupied during a space spray treatment, all electronic equipment should be well covered and the space should be ventilated for at least several hours before reoccupation. Location of the ants' entry points (and the nest itself, if possible), injection of pesticide into these crevices and sealing up afterwards are the standard measures to prevent future swarming.