Major workers are the dominant caste in foraging parties of Macrotermes michaelseni; they also have the largest sternal gland, with the highest potential trail-laying activity. The termite utilizes pheromonal trails along open-air foraging routes, surface galleries and in the subterranean gallery network. Thus, surface galleries appear to serve primarily as protective structures to foraging traffic, while trails lead foragers to food sites. Well-established trails on paper lost activity within 2–3 hr under open-air field conditions. In a choice situation, a trail leading to food source was 30–40 times stronger than that directed to an empty food chamber, suggesting that food influences trail-laying and recruitment behaviour of the termite.
