"dassel" flies--which have no sting--closely resemble another kind of
gadfly which has a sting. Nevertheless, this last kind is little
feared by cattle, while the first is so to an inordinate extent. The
laying of the eggs upon the skin is at the time quite painless, and
no ill consequences follow until long afterwards, so that we cannot
suppose the cattle to draw a conscious inference concerning the
connection that exists between the two. I have already spoken of the
foresight shown by ferrets and buzzards in respect of adders; in like
manner a young honey-buzzard, on being shown a wasp for the first
time, immediately devoured it after having squeezed the sting from
its body. No animal, whose instinct has not been vitiated by
unnatural habits, will eat poisonous plants. Even when apes have
contracted bad habits through their having been brought into contact
with mankind, they can still be trusted to show us whether certain
fruits found in their native forests are poisonous or no; for if
poisonous fruits are offered them they will refuse them with loud
cries. Every animal will choose for its sustenance exactly those
animal or vegetable substances which agree best with its digestive
organs, without having received any instruction on the matter, and
without testing them beforehand. Even, indeed, though we assume that
the power of distinguishing the different kinds of food is due to
sight and not to smell, it remains none the less mysterious how the
animal can know what it is that will agree with it. Thus the kid
which Galen took prematurely from its mother smelt at all the
different kinds of food that were set before it, but drank only the
milk without touching anything else. The cherry-finch opens a
cherry-stone by turning it so that her beak can hit the part where
the two sides join, and does this as much with the first stone she
cracks as with the last. Fitchets, martens, and weasels make small
holes on the opposite sides of an egg which they are about to suck,