eat other molluscs--he is carnivorous, a
flesh-eater; but these other molluscs do not wait to be eaten. As the
enemy draws near they retire into their shells, and shut themselves up
as tight as they can. The Whelk, however, is a clever burglar; he knows
how to make a way into the hardest of shelly houses.

His front part--we might call it a nose--will stretch out to a fine
point; and it contains a rasping tongue even harder than that of the
Periwinkle. He sets to work. Moving the rasp up and down, he drills a
neat round hole in the shell of the animal he is attacking. No shell is
safe from him; and no tool could make a neater hole.

When you next gather shells on the beach, look at them closely; in some
you will see where Mr. Whelk, the burglar, has been at work. He needs
but a small entrance to enable him to suck out his helpless prey at his
ease. Is it not strange that this creature, with a body as soft as your
tongue, should earn its living by breaking into houses made of hard
shell!

There are other molluscs which find their meals in this strange manner,
and many others which, like the Periwinkle, feed more easily on seaweed.
One of these, the Limpet, you can always be sure of finding at low tide;
indeed, there are so many Limpets on the rocks that it would be hard
_not_ to see them. You will know, if you have tried to force a Limpet
from its hold on the rock, how very tightly it clings. It is as if the
shell were glued or cemented by its edges.

Yet there is no glue or cement used, but only a simple dodge. The Limpet
has a broad "foot," which almost fills up the opening of its shell. Like
the foot of the Snail, it is used when the animal wishes to take a walk;
but it serves another purpose too. It can be used as a sucker; and it is
this which enables the Limpet to cling so firmly to its rock.

When the tide is out, the Limpet clings to the rock, its soft body
tucked safely away in the shell. Its feeding time comes when the water
covers the rocks once more. Then the Limpet's shell may be seen to tilt
up, and a foot, and a head with feelers and eyes, come out. The Limpet
crawls to the seaweed and begins to browse, using a rasp like that of
the Periwinkle. It then crawls back to its own place on the rock. In
time this resting-place becomes hollowed out, and the Limpet's shell
fits into the groove thus made.

Limpets are useful as bait for fish. The Whelk and Periwinkle are
gathered in immense numbers, and are us