vin] RAT-FLEAS AND BAT-FLEAS 105 



wool. A portion of the rat's abdominal wall is left 

 exposed and shaved. The flea, in an inverted test- 

 tube, can then be put on the hairless patch of the 

 abdomen and given an opportunity of biting, which 

 it may or may not accept. 



When fleas are being collected from rats it has 

 been noticed that the true rat-fleas are usually on 

 the hind-quarters of the host, whilst the mouse-flea 

 prefers the region of the head and neck. 



As regards the tastes and habits of oriental rat- 

 fleas in the matter of food a long series of experi- 

 ments may be summarized in this way : 



(1) When many rat-fleas are present some will 

 attack man, even when a rat is available for their 

 food-supply. (2) When the number of rat-fleas is 

 small, and when their true host is present, they will 

 not attack man. (3) When rat-fleas are starved 

 they will readily attack all animals, not being 

 particular in the choice of a host. (4) Rat-fleas 

 deprived of their food for from 72 to 96 hours 

 attack and feed on man more readily than at other 

 times. (5) Rat-fleas, even when starved, prefer 

 their true host to man. (6) Rat-fleas may be 

 attracted to man, jump on him, but take some time 

 to feed on him. Plague-infected fleas might in this 

 way be carried from one place to another without 

 infecting the man ; but they would, when brought 

 near a rat, attack it in preference to man. 



