The genus Myrmecocystus is commonly known as "honeypot ants." Worker ants tend special polymorphic ants called repletes. These unusual ants hang from the ceiling deep within the nest and are "living storage units." They store large quantities of nutritious honeylike fluid in their swollen abdomens to feed the colony during times of famine and drought. This is an adaptation for living in extremely hot desert environments with prolonged drought, such as the Salton Sea region. The repletes of some species become the size of small grapes. During leaner times of the year when foraging food is unavailable, workers will tap their antenna upon the head, mandibles and antenna of a replete to solicit food, which is then readily provided to the repletes' nestmates. See the following image courtesy of Wikimedia Commons.