When the Greek eagle lifts the Greek tortoise in its talons, and lets it
fall from a height so that the strong carapace is broken and the flesh
exposed, it is making intelligent use of an expedient. Whether it
discovered the expedient by experimenting, as is possible, or by chance,
as is more likely, it uses it intelligently. In the same way
herring-gulls lift sea-urchins and clams in their bills, and let them
fall on the rocks so that the shells are broken. In the same way rooks
deal with freshwater mussels.