6 LEAFLET 147, U. 8S. DEPARTMENT OF AGRICULTURE 
liquid that can be purchased at drug or other stores. Upon exposure 
to alr it evaporates, forming a gas that is heavier than air, so it will sink 
into soil and cracks. This gas is explosive and inflammable in the pres- 
ence of fire in any form, so keep matches, lighted cigars, cigarettes, etc., 
away while using it.) Sometimes pouring boiling water into such 
cracks will lull 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. 
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 burrows 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 fumi- 
vation. 
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.—Sodium fluoride powder dusted about window sills, 
drainboards, foundations, and other places where ants crawl will often 
drive them away, but not always. If effective, it makes an easily 
applied and cheap control. Sodium fluoride is a poison, so do not get 
at onto food, and keep it away from children and pets. 
Chemical barriers.—Ants can be kept off tables, refrigerators, or 
other movable furniture of no particular value by placing the legs of 
the furniture in shallow dishes or small jars into which has been poured 
a small quantity of kerosene. Keep the surface of the kerosene free 
from dense accumulations of dead ants; otherwise live ants may use 
the bodies of those killed as a bridge to reach the legs of the furniture. 
Ant tapes fastened about the legs of furniture will keep ants off 
and are cleaner than the kerosene containers. Prepare these tapes by 
boiling, for a short time, strips of bias cloth tape in a saturated solu- 
tion of bichloride of mercury (corrosive sublimate). After boiling the 
strips, hang them up to dry, and later, as needed, wrap them about 
