340 



GENERAL ZOOLOGY 



more or less open country. The usual natural defenses of such 

 animals are speed and kicking ability, to which herding has come 

 to be an additional measure of protection. Carnivorous animals 

 such as the wolf occasionally hunt in packs, but the pack is 

 seldom large and its organization is purely temporary in character. 

 Wolves hunt in packs only when food is scarce. The members 

 of the pack are competing against each other to obtain food. In 

 a herd of antelope the benefit of association comes from the 

 increase in power to sense danger. Instead of depending on one 

 set of sense organs each member of the herd receives the benefit 



Worker Queen Drone 



Fig 192. — Honeybee. X 2. {From Phillips, U. S. Dept. Agr. Farmers' Bulletin 



447.) 



of the sense organs of every other member in perceiving danger. 

 Escape depends upon individual effort. In some cases of 

 gregarious animals, however, the herd acts as a unit in defending 

 its members. A herd of musk oxen held at bay by dogs forms 

 a circle, with the calves in the center, the adults having their 

 heads toward the outside. The protective value of herding in 

 such cases consists in multiplying the individual weapons of 

 defense by the number in the herd. 



Communalism. — In herding, all members of the group are alike 

 except for differences in sex. By communalism is meant a social 

 condition in which a species of animals lives in a group of a 

 permanent character, distinguished by a marked division of labor 

 among the members, and often accompanied by a physical 

 differentiation of the members. Such forms of social organiza- 

 tion have reached the highest degree of perfection among the 

 social insects, such as the honeybee and the ant. 



