THE COMMON SWIFT 47 



PLATE XXV 

 THE COMMON SWIFT (1) 



The "swift" moths owe their name to their 

 rapid flight, for they can all fly very swiftly 

 indeed when they are alarmed. But very often, 

 on a warm summer's evening, you may see them 

 in grassy places in woods swinging, as it were, 

 in the air— flying first a foot or so to one side, 

 and then a foot or two to the other side, over 

 and over again, just like the pendulum of a 

 clock. And when they are doing this they do 

 not seem at all ready to take the alarm, so that 

 you can easily catch them. 



Five kinds of these moths are found in the 

 British Islands, of which the Common Swift is 

 by far the most plentiful. It lives, not only in 

 woods, but also in lanes and on the borders of 

 fields, and on warm evenings in June you may 

 see it darting swiftly along almost any hedgerow. 

 And if you catch a dozen or so you will find 

 that the males are all spotted and streaked with 

 white, while the females are plain dingy brown 

 all over. And, besides that, you will see that no 

 two of the males are quite alike, some of them 

 having a great many more white markings than 

 the others. 



The caterpillar of this moth lives underground, 

 and feeds on the roots of dumb nettles. 



