244 INSECTS 



cate the nests if possible and destroy by injecting gaso- 

 line or bisulphide of carbon with a syringe. Both of these 

 are highly inflammable and should only be used where 

 there is no fire nor open artificial light of any kind. 

 Many colonies may be reached in this way and greatly 

 weakened or destroyed. Others will be so situated that 

 they cannot be reached, and the insects will simply seek 

 less exposed openings into the rooms. The systematic 

 campaign then consists of keeping all food products un- 

 der cover so far as possible, or protected by belts of cre- 

 osote or oil of lemon, which the insects will not readily 

 cross. Set out, easily accessible in their ordinary lines of 

 march, all the raw bones with small particles of adher- 

 ent meat that come from the kitchen, and when these 

 become covered with ants throw into the fire and 

 burn. Or with a knife scrape the surface of a piece of 

 meat and spread the scrapings thinly on a piece of 

 paper. Burn this when covered, in the same way, 

 always taking care to let none escape. Keep this up 

 consistently and persistently, and no matter how 

 numerous the ants may seem to be, they will become 

 so greatly reduced in numbers that the nests are dis- 

 organized for lack of workers. There will be no one to 

 feed or care for the young and the colonies will perish. 

 Instead of the meat and bone method the sugar-sponge 

 method may be employed. This means two moderate 

 sized sponges, saturated with sugar water and pressed 

 nearly dry. Place one near the run until the ants 

 swarm in all its cells; then remove and drop into boil- 

 ing water, substituting the second sponge in its place. 

 The boiling kills the ants, of course, and the sponge 

 should then be thoroughly washed to get rid of the 

 dead insects, again dipped into the sugar water and 

 prepared to replace the second sponge when that is 

 ready to be boiled. It is sometimes a matter of weeks and 



