32 MAMMALS. 



So extraordinary is the sensibility of this entire mem- 

 brane that several naturalists, Spallanzani among them, 



have attributed to these animals the posses- 



A sixth . ,. . , , , . , . . , . 



sense sion * a Slx ^ n sense, a hypothesis that rests 

 for the most part on the fact that, when arti- 

 ficially blinded, they have been known to fly clear of 

 threads suspended in a darkened room. Other observers 

 have testified to the remarkably keen sense of smell pos- 

 sessed by them. 



All bats are without doubt seen to greatest advantage 

 on the wing. On the ground, they shamble for the most 

 part very awkwardly, the long-eared bat by alternately 

 hooking on with the curved nail of the fore-thumb and 

 raising itself on its hind-legs, the rest running along with 

 bent head. Most bats can swim, though they do not take 

 to the water by preference, nor can they leave it without 

 some difficulty. 



Without exception, they suffer much from parasites, 

 numbers of small ticks, not unlike those associated with 

 house -martins, being found beneath the fur. They are 

 also preyed on by stoats and owls, and occasionally by 

 the hobby and kestrel. 1 



It is a mistake to regard bats as creatures of darkness, 

 for although the majority of species do not come abroad 

 until, at all events, the twilight, it is not by any means 

 uncommon to find a stray one or two about, especially in 

 early summer, at midday. 



They hibernate for various periods, some kinds in soli- 

 tude, others in pairs, but the greater part in colonies, in 



which each sex often keeps to itself, in old 

 Hibernating. 



ruins, caves, church -towers, or hollow trees. 



In this winter sleep they are usually found hanging head 

 downwards. Mild days will, however, tempt them forth 



1 It is a remarkable fact that a number of dogs show the greatest 

 reluctance to pick up a bat, the scent apparently affecting them ; and 

 Sir R. Payne-Gallwey records a similar objection in respect of dogs 

 retrieving snipe and woodcock. 



