175 



Puddling or digging is evidently a very cheap and handy means 

 of destruction if the nest is small and situated in friable or easily 

 dug soil, near to a supply of water. 



If, however, the nest is situated in brick Avork, among tree roots, 

 in rocky soil, or is very large and far from water, it must be evident 

 that puddling or digging would become a very troublesome and 

 expensive operation. 



Poisonous fumes should be used only on nests where they caii 

 be easily generated without danger to human life, and forced in, in 

 such a manner as to fill every portion of the nest. But if used in 

 situations where it is impossible to confine them for the required 

 time, or in places where the gases escape without filling the nest, the 

 application usually, fails. The fumes which are given off by a solu- 

 tion of Cyanide of Potassium are useful for destroying nests in some 

 situations, but as this chemical is a deadly poison it requires to be 

 used with the utmost care 



Sulphur fumes forced into the nest seals the death-warrant of 

 all insects that are there at the time. This is effected sometimes 

 by a pair of bellows but is more economically accomplished by the 

 Asphyxiator, a machine much used in Europe for the testing of drains, 

 and the destruction of rats and mice in situations underground. 



It has been adopted in Trinidad for the purpose of destroying ants 

 nests, and there can be no doubt that for this purpose it is both 

 practical and effective when properly used. It consists of a small 

 chamber containing a centrifugal fan, much after the pattern of a 

 forge blower, which draws the sulphur fumes from a small combustion 

 chamber and discharges them into the nest through a rubber tube by 

 one of the main openings. In using the Asphyxiator, the chief 

 points are, to see that the fan is properly working, to see that the 

 combustion chamber is properly supplied with sulphur, and to see 

 that the orifices or openings of the nest are properly stopped as soon 

 as the smoke is seen to emerge therefrom. 



Coal tar is a very useful agent, but to try and force coal 

 tar upwards, or to place it, or any corrosive fluid, at the 



