570 THE AMERICAN NATURALIST. [VOL. XXXIV. 
one of the pictures of prehensile-tailed monkeys crossing a 
stream, the insects make good use of their long legs and hooked 
claws. These chains may persist for hours, but are more often 
soon broken as their weight increases. If some loose earth be 
placed in the bottom of the jar, the ants will be seen to carry 
little pellets of it in their mandibles as they file up the sides of 
the vessel and to use these as points of attachment for their 
feet and jaws during swarm formation. Termites placed in the 
jar are at once devoured. Their heads and other fragments 
of their bodies are afterwards used by the ants for the same 
purpose as the pellets of earth. 
It is evident that Æ. sumichrasti possesses in a very marked 
degree the power of swarming so characteristic of certain 
tropical Ecitons. The nomadic habits which have been ob- 
served in these forms were not observed in Æ. sumichrasti. 
During the winter and spring months, at least, the Ecitons 
I have observed occupy the same nest. This they probably 
continue to do till their young are raised. Belt has given an 
interesting description of the wandering and swarming habits 
of E. hamatum in Nicaragua. 
The Ecitons are singular amongst the ants in this respect, that they 
have no fixed habitations, but move on from one place to another, as they 
exhaust the hunting grounds around them. I think Eciton hamata does 
not stay more than four or five days in one place. I have sometimes come 
across the migratory columns. They may easily be known by all the com- 
mon workers moving in one direction, many of them carrying the larve 
and pupe carefully in their jaws. Here and there one of the light-colored 
officers moves backward and forward directing the columns. Such a 
column is of enormous length, and contains many thousands if not mil- 
lions of individuals. I have sometimes followed them up for two or three 
hundred yards without getting to the end. 
They make their temporary habitations in hollow trees, and some- 
times underneath large fallen trunks that offer suitable hollows. A nest 
that I came across in the latter situation was open at one side. The ants 
were clustered together in a dense mass, like a great swarm of bees, hang- 
ing from the roof, but reaching to the ground below. Their innumerable 
long legs looked like brown threads binding together the mass, which must 
have been at least a cubic yard in bulk, and contained hundreds of thou- 
sands of individuals, although many columns were outside, some bringing in 
1 The Naturalist in Nicaragua, pp. 24-26. London, 1888. 
