SHREWS AN 7 D BATS 287 



in one like lower Bengal, where perennial heat and 

 moisture secure the presence of innumerable insects, 

 is the extraordinary number and variety of the bats 

 who make their appearance every evening at sun- 

 down. Just then, and all through the time in 

 which the colours of the sunset fade out and 

 those of the after-glow burn up to replace them, 

 bats are emerging from their diurnal hiding-places 

 and hurrying out into the air. On every housetop 

 a softly scuffling sound issues from any disused 

 chimneys that project from the flat surface of the 

 terraced roof, and when one approaches one of 

 these and looks into any of the lateral openings, 

 bats will be seen coming scuttling backwards up 

 the shafts in a continuous stream. Each of them 

 as he reaches the top suddenly turns round so as 

 to bring his head upmost, has a quick look round, 

 scrambles to one of the openings, and then launches 

 forth into the air. Similar processes of emergence 

 are occurring simultaneously from innumerable other 

 pl aces from empty buildings ; from the crevices 

 about the beams in verandahs; from hollows in 

 trees, and from any sites presenting shaded and 

 obscure lurking-places so that it is little wonder 

 that, for a time, the sky seems to be alive with 

 myriads of bats, who flicker around in complicated 

 and changeful mazes. The first species to emerge 

 are mostly of very small size, many of them hardly 

 larger than big moths. These come out while the 



