306 



ANTS 



ANTS 



229. Antirrhinum maurandioides, in bud. 



(XH) 



the air, except at the swarming period. The style of 

 construction and the materials used by ants in making 

 their nests vary with the different species and with the 

 environment in which the animals live. Moreover, the 

 nests are very irregular, especially when compared with 

 those of wasps and bees. 



The passageways of the nests are enlarged here and 

 there into comparatively large cavities, or chambers. 

 It is in these different chambers that the activities of 



the colony are 

 conducted. The 

 queen lies deep 

 within the in- 

 terior of the 

 nest in a dry, 

 dark chamber. 

 Here she is care- 

 fully tended and 

 fed by the work- 

 ers who bear the 

 eggs as they 

 are laid, to other 

 chambers and 

 zealously care 

 for them. Many 

 insects never 

 see their young; 

 others may see them but do not care for them; others, 

 like the bees and wasps, put food into the gaping 

 mouths of their young but have no further associa- 

 tion with them. The ants, however, stand alone among 

 insects in their very intimate relations with their 

 progeny from the egg to the adult. Some of the cham- 

 bers in the nest are reserved for the eggs, some for the 

 larva, and some for the pupae. If, as often happens, the 

 eggs, larvae and pupae are all in one chamber, then they 

 are each grouped by themselves in separate piles, re- 

 minding one, as Lubbock says, "of a school divided 

 into five or six classes." In the simpler and more 

 primitive ants, this grouping and separation, may not 

 be so distinct. The ants are constantly transferring 

 their young from one part of the nest to another in 

 search of the right degree of moisture, temperature, and 

 the like. In the warm part of the day, the young will be 

 transferred to near the surface but at night will be 

 carried down again away from the cool air. The ants 

 are constantly cleaning the young, earing for the eggs 

 to prevent mold from growing on them, helping the 

 callow ants to emerge from their cocoons, bringing 

 food, cleaning, enlarging and reconstructing the nest 

 and doing thousands of things contributing to the com- 

 fort, growth and happiness of the community. 



The relation of ants to plants and to insects. 



It has been argued and many observations have been 

 offered to show that there is a most intimate relation 

 between ants and many kinds of plants. Certain observ- 

 ers think that many plants not only offer special in- 

 ducements to attract ants to them by affording favor- 

 able nesting-places, but also offer the ants delectable 

 food in the way of a sweet liquid, the floral and extra- 

 floral nectar. In return for the domiciles and the food, 

 the ants are supposed to protect their plant hosts from 

 certain insect and other animal enemies. In other 

 words, the relationship is one of mutual benefit, or a 

 symbiotic one. It is certainly true that many species 

 of ants make their homes in the hollow stems of plants, 

 in the thorns of acacias which the ants easily hollow 

 out (see Bull-horn Acacias), in cavities in bulbs, leaves, 

 and so on, and in the dried seed-pods of plants. It is 

 also true that ants assiduously collect and carry to 

 their nests the sweet nectar excreted by many plants. 

 It is not so clear, however, that these favorable nesting- 

 places and the nectar are provided by the plants on 

 purpose to attract the ants, nor is it clear that the ants 

 afford the plants protection from their animal enemies. 



In other words, more definite proof is needed to show 

 that the relation between ants and plants is a pur- 

 posely mutual one. 



On the other hand, the relation of ants to plant-lice, 

 tree-hoppers and certain scale insects is clearly, in many 

 cases, a mutually helpful one. Especially is this trur of 

 the relations between ants and plant-lice. The aphids 

 secrete a sweet liquid material known as honey-dew, of 

 which the ants are very fond and which they are 

 active in collecting and carrying to their nests. It can 

 hardly be supposed that the aphids excrete the honey- 

 dew solely for the ants. The liquid is an excretion from 

 the alimentary canal and is exuded whether ants are 

 in attendance or not. On the other hand, ants are very 

 solicitous in their care of aphids in return for the honey- 

 dew. The ants sometimes build "sheds" over the lice 

 for their protection and sometimes take the lice into 

 their own nests to care for them. In the case of the 

 corn-root louse, the ants collect the eggs of the aphid 

 in the fall, carry them into their own nests, and care for 

 them all winter. In the spring, the newly-hatched 

 aphids are carried out by the ants and placed in bur- 

 rows dug beforehand among the roots of certain early 

 food-plants. Later, the ants excavate burrows along 

 the roots of the corn and transfer the aphids to these 

 plants. 



It is interesting to watch the ants collecting the 

 honey-dew from the aphids. An ant approaches a 

 louse and gently strokes the latter with its antentur, 

 whereupon the aphid exudes a drop of the sweet material 

 which is quickly gathered up by the ant. This action 

 may be repeated with three or four of the aphids until 

 the ant has all it desires, when it hurries down the stem 

 of the plant and away to its nest with its load of sweet 

 provender. 



The life-history of ants. 



Enough observations have now been made to enable 

 us to say that most, if not all, colonies of ants are 

 started by a solitary queen or occasionally by two queens 

 working together. The queen, after the swarming 

 period, alights, breaks off her wings, and digs a burrow 

 in the soil or in decayed wood, forms a small chamber, 

 and then closes the opening. Here she remains until 

 her eggs are laid and have hatched into small larvae 

 that finally mature into normal but diminutive workers. 

 All this time the queen has taken no food but has lived 

 and fed the first workers on the reserve material in her 

 body. The small workers now begin to enlarge the 

 nest and soon other larger workers are reared and the 

 community begins to multiply and increase. 



The eggs laid by the queen are small and white 

 and rarely seen by the ordinary observer. These are 

 solicitously cared for by workers and finally hatch 

 into white, footless, soft, grub-like larva;. The larvae 

 are also tenderly cared for by the workers and changed 

 from chamber to chamber in conformity with varia- 

 tions in temperature and moisture. The workers 

 feed the larvae either on food which has been predi- 

 gested and which the workers now regurgitate, or on 

 bits of dead insects, leaves, or seeds that have been 

 chewed fine. The larvae finally, after attaining their 

 growth, change to whitish pupae which, in some species, 

 are inclosed in cocoons, while in others they are not. 

 These the workers treat with the same solicitude and 

 care that they show toward the larvae. The pupae are 

 often mistaken for eggs. Often, on raising up a flat 

 stone, one will see the workers running this way and that 

 with the larvae and pupae in their jaws, evidently seek- 

 ing a place of safety for them. The pupae finally trans- 

 form to the adult ants of the various forms, workers, 

 queens, and males. 



Economic importance of ants. 



Ants, as a whole, may probably be considered as 

 agents in making the earth more habitable for man. 



