w you
how.

Just watch for a minute the buffalo in the middle of the crescent; he
is the leader of the herd. We can see him only from the back; but as
he is the biggest and tallest buffalo there, we can make him out quite
easily. He is grazing quietly, and then moving along.

But see, what is he doing now? Why, he is looking up, straight ahead
of him! No, he sees no danger there. So he gives a glance to his
right, and then to his left. No, there is no danger there either. So
he puts down his head, and starts feeding again.

Thus, you see, every now and again he looks to see that no danger is
coming from anywhere in _front_ of the herd.

But what if any danger came from the _side_ of the herd,--right near
the end of the crescent,--or even from the _back_ of the herd?

_Buffalo Sentinels_

Let us see what the two buffaloes at the two ends of the crescent are
doing. They are the watchers, or _sentinels_, as they are sometimes
called. They keep a lookout nearly all the time.

Do you see the one on our left? After every two or three mouthfuls he
stops, and takes a look around; he even looks right to the back. Then
he takes four or five strides to catch up with the herd, and starts
grazing again. Then in a minute or two he takes another look around in
the same way.

And the sentinel on our right is doing just the same. Yes, the herd is
quite safe; the two sentinels are sure to see if any danger comes
from their side or from the back.

"But will not the sentinels have less to eat, if they are watching
half the time?" you may ask.

Yes, that is quite true. So all the Papa buffaloes take turns being
sentinels. After a while the two sentinels from the ends move up
toward the middle, and the next ones then begin to keep watch. And
they keep changing places like that from day to day. That makes it
quite fair for everybody.

When they go to sleep also they are arranged in the form of a
crescent; but the two ends are closed up, so that the Papas make a
ring, while the Mammas and the children sleep inside the ring.

When the Papas lie down, they are closer together than when they are
feeding; and they still keep their heads pointed to the outside of the
ring, so that they can get up in a minute, and be quite ready to drive
off any tiger. Of course they have sentinels keeping watch all the
time.

But now let us see other wonderful things that the buffaloes do, while
they are feeding.

We must be very careful how w