76 THE BOOK OF THE FLY 



liquid fly-poison, as is sometimes done, to serve as a 

 sop and as a standing stage. However, there is one good 

 lure well worth mentioning ; it is beer-dregs with or 

 without a little sugar ; moistened yeast is good, and the 

 advantage of beer-dregs with just a little sugar is due 

 to the mild yeast-like odour of slow fermentation, 

 which may fail if formalin be the insecticide ingredient. 



The handiest and safest preparation of fly-poison is 

 that sold in the form of a dry flypaper, which is said 

 to contain arsenic as the deadly ingredient. A very 

 small piece of one of the sheets ordinarily sold should 

 be placed on the summit of an inverted saucer ; a mere 

 spoonful of water now and then will suffice to moisten 

 the same ; there is little or no advantage in sprinkling 

 a little sugar thereon, unless beer-dregs are added. 

 This plan of using moistened poison paper is clean ; it 

 is safer than using a more fluid bait, and the ingredient 

 is certainly efficient ; the slightest taste thereof by an 

 inquisitive fly ensures its speedy death. Another 

 poison which has been recommended is a strong 

 decoction of tea-leaves, to which a little sugar and 

 beer may perhaps be added. 



It is said that the smell of geraniums is odious to 

 the house-fly, and so pots of these plants may be grown 

 beneficially on window-sills. Certain other odours 

 and scents are believed to be likewise more or less fly 

 deterrent, but their use is not effective warfare against 

 fly propagation. Paraffin painted on window-sills is 

 said to be very efficient. 



Flies may be easily prevented from entering the 

 open windows of any room, which has windows only 

 on one side, by the use of Venetian or louvre blinds or 



