at night, until they burn themselves. It has often been wrongly thought
that they are fascinated. We ought first to remember that natural
lights, concentrated at one point like our artificial lights, are
extremely rare in Nature. The light of day, which is the light of wild
animals, is not concentrated at one point. Insects, when they are in
darkness--underground, beneath bark or leaves--are accustomed to reach
the open air, where the light is everywhere diffused, by directing
themselves towards the luminous point. At night, when they fly towards a
lamp, they are evidently deceived, and their small brains cannot
comprehend the novelty of this light concentrated at one spot.
Consequently, their fruitless efforts are again and again renewed
against the flame, and the poor innocents end by burning themselves.
Several domestic insects, which have become little by little adapted to
artificial light in the course of generations, no longer allow
themselves to be deceived thereby. This is the case with house-flies.

Bees distinguish all colours, and seldom confound any but blue and
green; while wasps scarcely react to differences of colour, but note
better the shape of an object, and note, for instance, where the place
of honey is; so that a change of colour on the disc whereon the honey is
placed hardly upsets them. Further, wasps have a better sense of smell
than bees.

The chief discovery regarding the vision of insects made in the last
thirty years is that of Lubbock, who proved that ants perceive the
ultra-violet rays of the spectrum, which we are unable, or almost
unable, to perceive.

It has lately been proved also that many insects appreciate light by the
skin.

They do not see as clearly as we do; but when they possess
well-developed compound eyes they appreciate size, and more or less
distinctly the contours of objects.

Ants have a great faculty for recognition, which probably testifies to
their vision and visual memory. Lubbock observed ants which actually
recognised each other after more than a year of separation.

_III.--Smell, Taste, Hearing, Pain_

Smell is very important in insects. It is difficult for us to judge of,
since man is of all the vertebrates except the whales, perhaps, the one
in which this sense is most rudimentary. We can evidently, therefore,
form only a feeble idea of the world of knowledge imparted by a smell to
a dog, a mole, a hedgehog, or an insect. The instruments of smell are
th