6 LEAFLET 147, U. S. DEPARTMENT OF AGRICULTURE 



as it often is, out of doors, or in the soil beneath a cracked cement 

 basement floor. If the worker ants are proceeding from a crack in 

 the cement of the driveway, from between the bricks of a walk, or 

 from a similar place, merely pour 1 or 2 tablespoonfuls of carbon 

 disulphide down the crack and repeat this after 24 hours if necessary. 

 Carbon disulphide is a liquid that can be purchased at drug or other 

 stores. Upon exposure to air it evaporates, forming a gas that is 

 heavier than air, so it will sink into soil and cracks. I 1 his gas is 

 explosive and inflammable in the presence of pre in any form, so keep 

 matches, lighted cigars, cigarettes, etc., away while using it. Some- 

 times pouring boiling water into such cracks will kill the colony, but 

 not if it is deep-seated. If the nest is in the soil of the lawn or 

 garden, as indicated by the characteristic ant hills, make holes about 

 a foot apart over the infested hill area with a broom handle, or 

 similar object, to a depth of 2 to 4 inches and pour into each hole from 

 2 to 3 tablespoonfuls of carbon disulphide. Then close the holes at 

 the surface by pushing the soil together. With large ant hills it may 

 be necessary to make deeper holes and pour in more carbon disulphide. 

 Place the liquid below the roots of the grass ; otherwise, the grass may 

 be killed. 



Ant colonies may often be killed out by a single treatment with 

 10-percent DDT powder. Blow the powder into the entrance to the 

 nest and around the immediate vicinity of the ant hill or the places 

 where workers are active. If ants reappear later, another application 

 should be made. 



When nests are in the woodwork, find the small openings made by 

 the ants, or, if the nest is close to the surface, make an opening into 

 the ant galleries. Inject through these openings, by means of a 

 pipette or small syringe, a teaspoonful or tablespoonful of carbon 

 disulphide or orthodichlorobenzene, and then close the opening with 

 a plug of plastic wood, putty, or similar material. As the ant bur- 

 rows or galleries may be widely separated, it is desirable to make 

 injections through all the openings to the exterior that can be located. 



If it is suspected that the ant nest is near a certain point in the wall 

 or floor, it may pay to inject a small amount of carbon disulphide or 

 orthodichlorobenzene at that point, but this kind of treatment for 

 nests in a building is likely to fail unless the exact location of the nest 

 is determined. Ants often crawl considerable distances in wall and 

 floor spaces from their nests to the point where they emerge into the 

 room, and the colony is then too well protected to be killed by 

 fumigation. 



What to Do When the Colony Cannot Be Located 



When colonies cannot be located without tearing out partitions, or 

 going to other expense not warranted, the use of poisoned sirups, or 

 baits, powders, sprays, or chemical barriers, is advocated. No one 

 bait or sirup can be depended on to destroy all kinds of ants under 

 varying conditions. Some ants will eat one poison and refuse another ; 

 some eat only sweets, while others eat only meats and grease. 



Powders. — Ten-percent DDT or sodium fluoride powder dusted 

 about window sills, drain boards, foundations, and other places where 



