HONEY-DEW 51 
from this family of insects as a secretion. Its presence where 
no insects are present is accounted for by the fact that quantities 
of the liquid are expelled by the insects from a higher point, and 
in falling it appears on the leaves on lower levels. 
Several plants exude a sweet substance which the bees some- 
times gather, but it is quite a different material from honey-dew. 
In seasons of scarcity of nectar the bees will seek any sweet 
material. At such times they are troublesome about cider mills, 
where they eagerly fill their honey sacs with the rich juice of the 
apple. They may even be found, at times, on decaying fruits 
which have been broken open. The saps from numerous plants 
when exposed by injury are freely sought. These substances 
are not honey-dew, though they are likely to be stored in the 
same manner. 
The plant lice, or aphids, have a remarkable life history. The 
first generation of young to appear in spring is hatched from 
eggs and all are females. These in turn give birth to living 
young, but no males appear until several successive generations 
of living females have been brought forth. As the season 
advances males also appear and the cycle starts all over again. 
There are many different species much sought for by ants. 
The solicitude of the ants toward the insects gave rise to the 
old story that ants keep cows. They do, in fact, seem to care for 
the plant lice for the purpose of securing the honey-dew which 
they secrete. The ants also use the bodies of the plant lice as 
food. It will thus be seen that the comparison of the ants and 
their herds is not so far wrong, for while the liquid secretion may 
be called milk, the ants may also be said to secure meat by the 
consumption of the plant lice themselves. With some species the 
ants are even believed to go so far as to carry the eggs of the 
plant lice down into their own nests to be cared for during the 
winter months, and to place the newly hatched aphids in position 
on their food plants in early spring. 
Ants are not alone in their fondness for honey-dew, even 
though they may be alone in caring for the plant lice. Many 
