428 INTRODUCTION TO ZOOLOGY CHAP. 



This observation nest or " formicarium " should be constructed so 

 that there is one chamber (the "nursery" chamber, Fig. 320, A) which 

 is formed of two horizontal sheets of glass, separated only by a space 

 about ^ inch deep which is filled with finely sifted damp earth from 

 the original nest ; in this narrow layer of soil the ants can burrow 

 without ever being able to hide themselves. Communicating with 

 this chamber is a larger one with a wooden bottom and a glass 

 roof, the space between the two being as much as an inch. In 

 this "playground room" (Fig. 320, G) little banks of earth can be 

 made, and small tufts of grass or other plants introduced. In it 

 is also a small trough for honey or other food. 



Such an extra deep room is desirable, not only because it 

 affords the ants scope for freer, more natural activities than the 

 confined space of the " nursery-room," but also on account of the 

 ease with which a new colony of ants dug up from the garden or 

 field can be introduced into it. 



FIG. 321. Section across the Nest shown in Fig. 320. 

 Lettering as before. 



In preparing the nest for the new colony, care must be taken 

 that the narrow passage between the two chambers is not blocked ; 

 also it is desirable to make a path in the soil, leading from the 

 entrance into the centre of the "nursery." This chamber is then 

 darkened by a cover being placed over its glass roof, and it is thus 

 rendered attractive to the ants who, as a rule, shun the light. The 

 colony of ants which has been obtained is now introduced into 

 the undarkened "playground" chamber, the queen being gently 

 lifted with a camel's-hair brush. Very soon some of the ants will 

 discover the entry to the darkened part of the nest, and will enter 

 it and explore. They will then return and apparently communicate 

 their find to some of the other ants, for more will now accompany 

 them to explore again. Finally they will approach the queen and 

 stroke antennae with her, after which, in some cases, she will 

 go willingly with them to the new home. In other cases the 

 workers seem to use force ; one or two will seize her mandibles 

 with their own and pull her along, whilst others apparently 

 push her from behind. When once the queen is safely in, 

 some workers stay with her, but the others in great haste 

 return and begin to collect eggs, larvae, and pupae, and bring 



