84 BIRD HAUNTS AND NATURE MEMORIES 



but as time is precious the bat wastes no time in getting 

 to the scene of action. The speed of flight varies con- 

 siderably, but is usually rapid and straight, though varied 

 with occasional dashes from side to side and sharp oblique 

 dives. These erratic movements are, almost certainly, 

 due to the fact that the bat has become aware of an 

 insect at another level or on a lower plane. Bell thought 

 that they were caused, at any rate when the descent was 

 sudden, by the loss of balance if the bat had caught 

 " some large or intractable insect," and Grabham enlarged 

 on the idea and described the noctule using its thumb to 

 rend asunder the prey it was carrying. If the drop is 

 closely observed it will be seen to be not only direct, but 

 oblique; it is a dive, not a fall. 



Noctules frequently chase one another on the wing, 

 squeaking vigorously, and almost the whole time that 

 they are abroad they keep up incessant noise. This 

 sound, a high, shrill squeak, is uttered in the roost before 

 they emerge and after they have returned; Alcock points 

 out that the note may be imitated by striking a halfpenny 

 smartly with a sixpence. Bats are erratic about their 

 appearance in the evening; some nights hundreds are 

 visible, on others hardly one emerges. Doubtless to 

 some extent this irregularity is due to weather conditions, 

 cold, wind, or rain keeping many indoors; but a few go 

 abroad in stormy weather, and at times there are few to 

 be seen on evenings which are apparently suitable. 



The noctule has a curious smell, which White and 

 Donovan thought " fetid," but though strong it is not really 

 offensive; it has given rise, so some think, to the name 

 " fox-bat," but that may have originated in the colour 

 of the pelage. 



The habits otf any creature which comes abroad at night 

 or in the half-light of evening are not easy to observe, but 

 so easily does this bat adapt itself to the restraint of 



