INSTINCTS OF HARVESTING ANTS 29 



footsteps. It travelled from a foot to two feet distant 

 from its outward path, and consequently I do not 

 think the sense of smell could have been its guide. 

 I placed barriers between the returning ant and its 

 outward track so as to conceal any landmarks, and I 

 introduced stones and sticks as new landmarks along 

 the line of its return, but they did not in the least 

 confuse the ant. In front of one ant I placed a forceps, 

 a razor, a sheet of paper, a book, and a mirror. The 

 ant could never have seen such unusual landmarks 

 along any track, and if it made use of landmarks as a 

 means of recognizing its return journey, then such 

 strange obstacles as these must have convinced it 

 that it was on the wrong track. But the ant was not 

 confused ; it worked its way round the obstructions 

 and kept straight on. Nothing interrupted its home- 

 ward course ; nothing seemed to be its guide. It was 

 difficult to escape the conclusion that a powerful sense 

 of direction was the strange impulse that led it to 

 its home. Drawing the finger over the ground in 

 front of the returning ant did not excite it in the 

 slightest, though, if the same be done across the main 

 track leading from the nest, a great confusion ensues, 

 and only after much hesitation will the ants pass over. 

 This wonderful faculty by which the harvesters 

 engaged in funereal duties find their way home, and 

 which we must call a sense of direction, is, like other 

 instincts, capable of confusion. An ant had carried the 

 dead body of a companion nineteen feet distant from 

 the nest and was on the return journey. I took up 

 the ant and transferred it back to a point six inches 

 behind on its own track. After a pause the ant took 

 a few hesitating turns and then made straight for the 



