THE SOCIAL INSECTS 



The knowledge of the relative positions of numerous land- 

 marks is something different from being able to follow a 

 single beaten trail. Social wasps, also, learn to know a large 

 district surrounding their nest. An experiment by Gaul in 

 the U.S.A. provides a curious commentary on this fact. He 

 brought a nest from a mile away and put it in a hive. The 

 adult wasps all deserted their nest and brood and were found 

 building a new nest at a few feet from the original site. They 

 will only stay in their nest in the hive if they are shut up in 

 it for the first eight hours. 



As will be described later the honey bee has the further 

 power of communicating to its nest-mates information about 

 the location of sources of food. Most social insects, also, have 

 an advantage over most solitary ones in having a less rigid 

 type of behaviour. In many solitary wasps the successive 

 phases of nest-construction follow one another in a regular 

 sequence which does not allow for unforeseen accidents. 

 In Fabre's study of the wasp, Pelopaeus (now called Sceli- 

 phron), he found that when the mud-cells had been stored 

 with spiders, the whole group of cells was covered over with 

 an irregular daub of mud. If he removed the cells, the wasp 

 still daubed over the place where they had been. This irra- 

 tional rigidity is characteristic of all instinctive behaviour, 

 but is especially marked in solitary species, though there are 

 exceptions. No such complete rigidity is possible in social 

 wasps. The nest is growing all the time, and many different 

 jobs must be done in an order which depends on circumstances. 

 The wasps may have to fetch building material, or water, or 

 food, or add cells to the nest, or feed the brood. Thus each 

 individual worker has to do a greater variety of things than 

 any solitary species and must be prepared to do them in a 

 different order each day, since specialisation for particular 

 tasks is little developed in the wasps. 



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