TERMITES THRIVE BY USING VIBRATIONS

Termites are notoriously cryptic: infestations in houses are often discovered when an apparently intact timber object collapses, the archetypal 'falling through the floor boards'. This behaviour is adaptive because remaining undiscovered is the termite's primary defence against predators. However, being cryptic severely limits the ability of termites to explore their environment and assess potential food sources. Despite being blind and hidden, termites can assess a piece of wood swiftly after contacting only a small part of it (sometimes as little as a few square millimetres). Although termite soldiers have been known to produce vibratory alarm signals to warn conspecific workers, it is not until our sustained research over the last 10 years that termites have been shown to use vibrations as a principal tool for communications, making foraging decisions and detection. In this paper, some of our recent discoveries on the use of vibrations by termites will be discussed. These include the discovery of (a) two drywood termite species, Cryptotermes (Cr.) domesticus and Cr. secundus, using vibration signals produced as a byproduct of their feeding to assess food size; (b) the ability of Cr. secundus and Coptotermes (Co.) acinaciformis to discriminate material properties based on vibration signals; and (c) the amazing ability of the subterranean termites Co. acinaciformis to distinguish unloaded wood from loaded wood. Food size is just one factor termites consider when foraging; competitors and predators are also important factors. Our results show that Cr. secundus worker termites are able to discriminate their own species from the subterranean species, Co. acinaciformis, by eavesdropping on their competitors, while Co. acinaciformis can detect and avoid one of their main predators, ants of the species Iridomyrmex purpureus, using only vibrations caused by ants walking.