CONTROL WITHIN THE HOUSE 75 



common house-fly ; again, a saucer or shallow dish 

 with liquid contents is not a good method of presenting 

 the fatal bait. Placed on a table, or on a window sill, 

 or on a shelf, a saucer is liable to be tipped up and its 

 contents spilt ; moreover, the form of such receptacles 

 is radically faulty by reason of the strenuous walking 

 habits of the fly on the level. Out of many flies walk- 

 ing over a table ten or twelve may pass by, or round, 

 an overhanging saucer's rim to one fly that will mount 

 the same and sip inside. However, let such a saucer 

 or plate be placed on a table upside-down, and let 

 a slightly moist substance be placed in the shallow 

 central depression, which ordinarily is the base, then 

 the said ten or twelve flies will all mount and sample 

 the moist substance, even though it be not apparently 

 attractive in smell ; an inclined plane is ever an irre- 

 sistible invitation to mount and prospect the summit. 



It is another great mistake to suppose that an extra 

 tasty food material is desirable as a bait. The same 

 kind of mistake is made by people baiting a mouse 

 trap with toasted cheese, whilst a bit of dry bread, or 

 better still, a green pea, would much better entice a 

 common mouse. Strong smelling and saccharine 

 foods immensely attract the blue-bottle and the wasp, 

 which are thus enticed indoors and induced to become 

 occasional visitors to our tables ; but the house-fly 

 requires little of such lures ; indoors she is an inquisitive 

 prospector, who will never pass by any moist material 

 without testing its quality. Moreover, the use of 

 poisoned milk, or even jam, should be rather avoided 

 for fear of injury to dog or cat ; furthermore, it is 

 dangerous to place a piece of bread in a saucer of 



