188 SECRETS OF ANIMAL LIFE 
tree stems. This is all the more interesting if it be 
true that what the woodpeckers really eat is not the 
acorn but a kind of grub that develops inside it. 
Not a few mammals are in the habit of hiding 
away surplus food, and it is easy to imagine how 
this might lead on to a more definite storing instinct 
such as squirrels exhibit. In a number of different 
hoards the squirrel hides hazel-nuts, beech-nuts, 
and acorns, and these may be a stand-by in the 
hard times of winter when the beautiful creature, 
who is not a true hibernator, is unable to sleep away 
its hunger, or when the young ones, who remain 
for a long time in the company of their parents, 
plead for food. In some mild parts of the country 
the squirrel’s storing instinct seems to remain un- 
developed. There are other mammals, such as the 
marmots, who make their burrows comfortable 
with grass and shut the door when winter knocks; 
it is again easy to see that this might lead on to a 
definite hoarding of food supplies. Such hoarding 
is well illustrated by some of the light-sleepers, 
such as dormice, who awaken from their hibernation 
whenever the weather is mild and are then inclined 
to have something to eat. In the burrow of the 
hamster several store-chambers are made, and 
grain, as well as hay, is accumulated in considerable 
quantity. We read that the people of Kamschatka 
rob the granaries made by one of the voles (JZicro- 
tus @conomicus), and that the Mongolian herdsman 
brings his cow in autumn to eat the haystacks 
which are so diligently built in the summer months 
