Architecture in the Animal Kingdom. 93 



form and of the material used by different species. 

 With the mammals/ finally, nest constructions are, on 

 the average, far less complicated and artistic than with 

 birds and insects. 



The buildings which serve to shelter and rear the 

 young, may likewise be used as permanent lodgings 

 for parents and offspring. This is the case with social 

 insects and many mammals. Thus the nest develops 

 into a family dzvelling. Only in relatively rare 

 instances, do animals employ their building skill in 

 providing other necessaries of life. Many spiders spin 

 their webs not only as a hiding-place for themselves 

 or for breeding purposes, but they also, by means of 

 their spinning glands, manufacture nets wherewith 

 to catch their prey. In Hke manner the neuropterous 

 larva, which goes by the name of ant-lion, uses its 

 earth-funnel both as a dwelling place and as a trap for 

 catching its prey, which consists chiefly of ants or 

 other insects. Among ants, however, we find the most 

 varied and manifold application of natural architec- 

 tural skill. 



2. The Nests of Ants. 



In the first place, ants use their architectural talents 

 for building nests, in the strict sense of the word. 

 Everybody is more or less familiar with ant nests, but 

 few are aware of the immense variety of forms implied 

 in that apparently simple term. As there is scarcely 

 any material unfit for an ant nest, so it may assume 

 all possible shapes and be found in the most unlikely 



*) We shall consider more in detail the buildings of the beavers in 

 the subsequent pages. 



