GEOLOGIC WORK OF ANTS BRANNER. 823 



The armadillos, known in Brazil as tatus, are also ant-eaters. As 

 Mi-. Wallace points out, 1 the armadillos are highly characteristic 

 of tropical South and Central America, and at the time of the publica- 

 tion of his famous work on the geographical distribution of animals 

 they embraced 6 genera and 17 species, to say nothing of many 

 extinct species found by Lund in the caves of Minas Geraes. Some 

 of these armadillos are so large that a single individual will weigh 

 as much as 75 pounds, or even more. 



They live upon insects chiefly, and the white ants seem to be their 

 favorite food. They enter the nests by digging openings at the base 

 of the cones with their powerful fore feet. 2 



The white ants also form the principal food of the South American 

 ostrich (Rhea americana), which is the largest bird in tropical 

 America. 3 



In addition, there are large numbers of birds and reptiles, such as 

 toads, frogs, lizards, and snakes, that habitually feed upon these 

 insects. 



The true ants are enemies of the white ants worthy of especial 

 mention. The abundance of the ants and their pugnacious disposi- 

 tions make them serious obstacles to the development of the termites' 

 colonies, and they are probably their worst natural enemies. The 

 termites have in their colonies forms that are known among biologists 

 as soldiers, but so far as I have been able to determine from personal 

 observations these soldiers do not attack the true ants, though they 

 do take the place of soldiers in obstructing the passage of the ants into 

 the termites' nests and galleries. 



The result of the relations existing between the true ants and the 

 termites is that the two lands do not thrive together; at least I have 

 never found the termites' nests where the saubas or other true ants 

 were notably abundant. - Preyed on by the true ants and by animals 

 of so many different kinds, and even by insects themselves, it occurs 

 to one that their chances of survival in the midst of so many enemies 

 must be very small. That survival appears to be due largely to their 

 habit of living and working under the protection of their covered 

 roadways, and to the fact that their roads are constructed of mate- 

 rials that are remarkably inconspicuous. Nothing could look more 

 thoroughly abandoned and lifeless than the common run of white 

 ants' nests and their covered passages; yet if one breaks through 

 these coverings he will usually find them fairly swarming with life. 



My general impression is that those white ants which build mounds 

 of earth are especially abundant in the highlands of Minas Geraes 

 and through the semiarid portions of Sergipe, Bahia, Goyaz, Matto 



» Alfred R. Wallace: The geographical distribution of animals, vol. 1, pp. 245-246. New York, 1S76. 



2 The flesh of the talis is very much prized for food, and this naturally leads to the hunting and killing 

 of these animals, which should be protected. 



3 George Gardner: Travels iu the interior of Brazil, p. 280. London, 1840. 



