HOUSEHOLD INSECTS 255 



their sense of smell, is shown by the fact that if some 

 strong-smelling substance, such as paraffin, be laid in the 

 trail, the ants at once become confused and show, by 

 their aimless wandering, that they can no longer scent out 

 their original route. Except that light repels them, their 

 sense of sight is probably wanting, in fact experiments in 

 this direction all tend to show that they cannot see, in 

 the usually accepted manner; their sense of hearing too 

 is no better developed, though loud and sudden noises, 

 which cause a violent vibration of the surface of the earth 

 on which they are located, throws them into a state of 

 alarm. 



We have already mentioned that the workers are in the 

 habit of washing the larvae and pupae with their tongues, 

 but the adults are kept equally clean. Workers keep 

 themselves clean by rubbing their bodies and antennae with 

 their legs, which are in turn cleaned by being drawn 

 through their mandibles. Sometimes, when very dirty, 

 the workers will clean one another, and, on one occasion, 

 Professor Wilmon Newell " observed one worker industri- 

 ously cleaning the mandibles of a companion. During the 

 operation, which lasted for several minutes, the worker 

 receiving the kindly ministrations stood with her head 

 well raised, mandibles extended, and feet firmly braced, 

 while the teeth of her mandibles were thoroughly cleaned 

 by those of her sister." The queen usually attends to her 

 own toilet, but is, occasionally, cleaned and groomed by the 

 workers. Dead adults or larvae and decaying animal or 

 vegetable matter are not tolerated for a moment, but are 

 promptly removed to a distance or, if too large for removal, 

 are buried, the ants carrying particles of earth with which 

 to effect the interment. Unlike many other species of 

 ant, Iridomyrmex humilis does not store up food in its 

 nests, against emergencies ; food is taken into the nests, in 

 plenty, but experience shows that it is promptly consumed, 

 within a few hours. The foraging workers are in the 



