INSECT SUCKERS AND BITERS. 203 
no means asleep but very busy, for their mouth, 
which, like that of all other insects, is composed of 
six parts, is so formed that they can plunge it deep 
into the stem and suck and suck all day, filling their 
round green bodies with sweet sap. A wonderful 
little mouth it is, the two lips being joined together 
into a kind of split tube, out of which are thrust the 
four jaws, in the shape of long thin lancets, to pierce 
the plant. When once these insects have fixed 
themselves they never seem to tire of sucking, but 
take in so much juice that, after passing through the 
body, it oozes out again at the tail and the tips ot 
two curious little tubes (t, Fig. 69) standing up on 
their backs. This juice, falling on the stems and 
leaves of the plant, covers them with those sticky 
drops often called " honey-dew." 
It cannot be said that these little insects lead 
very exciting lives, for they make no homes, neither 
do they take any care of their young ones, and only 
move about when they wish to fix upon some new 
spot; and yet they are very interesting, both because 
the ants visit them to sip their sweets, as we shall 
see in Chapter XII., and also because they manage 
to live in such numbers in spite of being so helpless 
and stupid. 
The secret of this is that they have a special way 
of sending young ones into the world. If you look 
at a stem covered with plant-lice towards the end of 
the summer, you will find among the wingless sucking 
insects some larger ones straggling about the plant (B, 
Fig. 69) which have delicate transparent wings. These 
are the fathers and mothers, whose wings have grown 
gradually under their splitting skins, and they will 
