POISONOUS INSECTS 2S7 



off, and do not again quit the nest. In addition to the ordinary- 

 workers, there is in some species a second, or rather a third, form of 

 female. In ahiiost any ants' nest we maj see that the workers differ 

 more or less in size. 



The food of ants consists of insects, great numbers of which 

 they destroy; of honey, honey-dew, and fruit — indeed, scarcely any 

 animal or sweet substances comes amiss to them. Some species — such, 

 for instance, as the small brown garden ant — ascend bushes in search 

 of aphids, which are called the ants' cows. The ant then taps the 

 aphis gently with her antennae, and the aphis emits a drop of sweet 

 fluid which the ant drinks. Sometimes the ants even build covered 

 ways up to and over the cows, which they protect from other insects. 



It is a curious fact that in some parts of the world ants are eaten 

 and regarded as great delicacies. The Siamese particularly are noted 

 as placing ants eaten with red pepper or curried on their menus. They 

 also serve them rolled in green leaves with shreds of pork. 



Another curious fact is that formic acid was first made from ants. 

 They were either placed on a cloth and hot water poured over them, 

 this water afterward containing the acid, or the ants were placed in a 

 retort of glass with water and the retort heated. The vapor distilled 

 over contained formic acid. 



Locusts. — While they do not attack mankind, yet the locusts arc 

 perhaps the most serious pest that the African farmer has to contend 

 with. This insect, shaped much like the familiar grasshopper, often 

 appears in great swarms, devouring every twig, green shoot, leaf and 

 bud, in addition to whole fields of grain. They cover the ground so 

 thickly that it is said that the footprints made by a horse among them 

 are filled up in a few seconds. In 1798 South Africa for a space of 

 two thousand square miles was completely covered with them. 



It is only fair to the locust to state, however, that the native 

 reciprocates for the destruction of his crops by eating the locust in 

 turn. Their method is to gather great quantities of live locusts, place 

 them in ovens previously heated by a very hot fire, cover them up and 

 leave them to bake. The next process is to spread them out in the 

 sun to dry, taking care that the other locusts do not eat them. When 

 thoroughly dried, the process taking two or three days, the locusts are 

 ground up into a powder with which a sort of pudding is made. 



