I found a nest of large carpenter-ants (_Camponotus atriceps_, var. _esuriens_, Smith) which had made their home in fallen timber. Upon examining their work, it was evident they must have strong tools to work with, for the numerous rooms and chambers of their domicile were often made in firm, hard wood. They are the largest, most vicious species I have ever seen. I introduced one of these terrible creatures into the jar among the quiet, peaceful occupants. A large worker major immediately closed with her: it was so quickly done that I could not tell which was the attacking party. They rolled about a few moments in a close embrace, till they rolled out of sight through the wide entrance to one of the rooms below. There was considerable excitement and increased activity among the workers, who were constantly bringing to the surface bits of earth which the struggling warriors had loosened. In about an hour the head of the carpenter was brought out, divested of every member: both the antennæ and palpi were gone, cut close to the head. A little later the abdomen was brought out, and still later the thorax with not an entire leg left. [Illustration: QUEEN: SIDE-VIEW, SHOWING PECULIAR CONFORMATION OF THE THORAX.] Several times during the months of January and February I introduced into the jar a number of half-grown larvæ of the harvester. Without any hesitation they were quickly carried to the rooms below by the workers minor. On the 4th of February I found a large number of the larvæ of the carpenter-ant (_Camponotus meleus_, Say). They were very small, and closely packed together in a chamber cut out of hard wood, two inches in length and an inch and a quarter in diameter, nearly circular. It was packed full of larvæ and eggs, the larvæ apparently just hatched. I detached a small mass, all stuck together, and placed them in the jar with the harvesters. The workers minor immediately surrounded the mass, touching it with their antennæ, and then retreated backward, passing their fore legs over the head and antennæ, as if the larvæ were obnoxious to them. Great commotion ensued, followed by an apparent consultation lasting a few moments; but soon the usual quietness reigned, and most of the ants left the helpless larvæ and returned to their mining and to the storing away of seeds or feeding their own young. But two or three had not entirely deserted the young carpenters. Again and again they touched them, and then retreated, cleansing the antennæ as they moved backward. At last one seized the mass and held it in her mandibles, standing nearly in an upright position. Several workers now surrounded her, picked the larvæ off, one by one, and carried them below, until all were separated and disposed of.