A butterfly is a flying insect
that lives primarily on nectar
from flowers. When touched
by humans they tend to lose
small numbers of scales, that
look like a fine powder. If
they lose too many scales the
butterfly's ability to fly will be
impaired. Several species of
butterflies need more sodium
than provided by the nectar
they drink from flowers. As
such, they are attracted to the
sodium in salt. Since human
sweat contains significant
quantities of salt, they
sometimes land on people, to
the delight of the young at
heart everywhere.
