DRIVER ANT, a nomadic predatory ant which makes its forays in column-like masses. The term usually refers to the well-known spe cies (Dorylus, or Annoma, arcens) of west ern Africa; but the genus embraces several species scattered over Africa, and others in southern Asia and the East Indies. All be long to the formicid sub-family Dorylinae, which also includes the highly destructive visiting, or foraging, ants (Eaton) of tropical America. The driver ants are reddish brown, and in general (i.e. the workers and soldiers of vari ous castes) small, rarely exceeding one-third of an inch long; but the females and males are huge, ungainly creatures an inch and a half in length. All except the procreative males are totally blind. Most of the species live almost continuously underground; but the cele brated West African driver (Dorylus arcens) has a more exposed manner of life. Its colonies construct no fixed home underground or else where, but move about incessantly, taking shel ter during the days in crevices of rocks, under logs, and so forth. Frequently they climb trees, and then hang in clusters, or in long chains that grow until they find an attachment for•the lower ends when they serve as ladders up and down which other ants climb.
When they move on one of their expeditions they go at night or in cloudy weather. If de tained abroad collecting food until the morning sun is shining, they will construct an arch over their path, as they proceed, of dirt agglutinated by a fluid excreted from the mouth. They march in an army-like column of millions of individuals, which 'looks like a thick rope,' and is flanked by lines of watchful Against an excursion of these desperately pug nacious little insects, nothing avails on the part of any beast of the forest but instant flight. 'The most fierce and powerful animal,*
Hamilton asserts, 'and the most deadly snake, become, in the face of their attack, mere panic stricken fugitives, rushing vainly for relief to the nearest water, or desperately rolling on the earth in their endeavors to free themselves from the torture of a million poisonous bites.' Animals tied or confined in pens or cages, such as calves, pigs or fowls, will be killed and stripped of flesh to the bones, as has often happened; and a sleeping man wakened by such an onslaught will have hard work to save his life. A sick man, or an infant, will perish. Dr. T. S. Savage, the celebrated American missionary to the Gaboon region, who first described the gorilla scientifically, had much experience with invasions of his premises by these ants. The first effect of their entrance into a house is the flight or capture of rats, cockroaches and every sort of vermin. Insects, indeed, form their principal and ordinary fare. They ransack the building in regular order, searching for food, preferring fresh meat and fresh fruit-oils, and not touching sugar, milli, salted meat. When the place is to their satisfaction the whole army leaves it completely and goes on. These habits characterize this West African species in par ticular. Other species are not so migratory or predaceous. Consult Savage, 'Proceedings,' Academy of Sciences, Philadelphia (Vol. IV, 1847) Wheeler, (New York 1910); Hamilton, 'Animal Life in Africa) (New York 1912).