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released shortly thereafter, it makes a beeline in the direction its hive 

 would have been had it not been moved. Arriving at the wrong site, 

 it circles and eventually travels in a fairly straight line to its hive. This 

 is diagrammed in Figure 3b. 



Not only can bees find their way to the hive by the angle with the 

 rays of the sun, but they also communicate to other bees the location of 

 a new source of food in terms of this angle. When a bee finds such a 

 source, it goes through a complicated dance pattern on the side of the 

 hive. The amplitude of the pattern communicates the time of flight 

 and the predominant angle with the vertical reveals the angle between 

 the flight path and the sun's rays. 



Bees and other insects have vision extending into the ultraviolet; this 

 portion of the sun's spectrum is useful to insects but not to mammals. 

 There are reports that bees can sense not only the direction of the sun's 

 rays but also their polarization. Other reports indicate that the 

 apparent ability to sense polarization is misleading. (It should be noted 

 there is a small polarization effect in human vision which can be just 

 barely demonstrated by psychophysical tests.) Whether or not the 

 bees use the angle of polarization, their precision in comparing their 

 flight path with the angle of the sun's rays is far beyond anything humans 

 can do without the help of physical instrumentation. 



5. Migration and Homing 



Although insects use the angle of the sun's rays to return to their homes, 

 they have other sensory information which allows them to "home" if 

 their angle computations have led them astray. Other animals such 

 as bats, fish, turtles, and pigeons also exhibit homing tendencies. It is 

 most likely that bats do not use any form of visual clues. Some evidence 

 indicates that fish and turtles, as do insects, use the sun in homing. One 

 type offish, the bass, probably has an internal clock and avoids the errors 

 made by ants and bees when imprisoned in the dark. 



Certain pigeons have been selected and bred for their ability to home. 

 These birds may be taken hundreds of miles from their nests in containers 

 which are completely covered so that they cannot see the surroundings. 

 Even though the pigeons have never been in that location before, many 

 are able to follow a very straight line to their nest. (However, they must 

 be trained over increasingly large distances starting with about 25 miles, 

 before the longest flights are possible.) 



Various theories have attempted to relate the pigeon's homing to a 

 combination of hypothetical senses. One of these postulated an extreme 

 ability to detect the angle of the sun and combine it with a very precise 



