Formosan subterranean termite soldiers have a teardrop-shaped head.
Formosan soldiers' mandibles are strong enough to latch onto exposed skin. When aggitated they also exude a white, sticky fluid from a hole at the top of thier heads. (Photo by Chris Dunaway.)
Formosan soldiers will quickly appear at any disturbance in the nest. (Photo by Chris Dunaway.)
The soldier caste in Formosan subterranean termite colonies exhibit several distinct differences from the soldiers of native subterranean termites. These differences are often the easiest way to distinguish between the two.
Formosan subterranean termite soldiers account for between 10-15 percent of the total colony population. Native subterranean termite species maintain the soldier level at about two percent of the colony's population.
Formosan soldiers are much more aggressive than those of the native species. They will quickly assemble at any breach in the tunnel network and attack any potential invader.
Formosan soldiers have powerful mandibles that are capable of pinching and latching onto exposed skin. Although there is no toxin, it can be very uncomfortable.
The head of a Formosan termite soldier is teardrop-shaped with the large end connected to the body and tapering to a point at the mandibles. Native soldiers have longer, nearly rectangular-shaped heads.
Finally, there is a hole on the top of the heads of Formosan soldiers that native soldiers lack. This hole is called a fontanelle. From the fontanelle, the Formosan soldiers can exude a sticky white fluid as a defensive device. This fluid is not toxic but can be very effective against invading ants.