> One of the "eye-opening" principles I learned in one of my introductory
> entomology courses in college (the professor was a bio-systematist)
> was that just as no two human beings are exactly the same, no two
> insects are exactly the same either.  Each one is an individual,
differrent
> in some way from all the rest.

Not only are there genetic and developmental differences, but as any
animal, individual bees differ in their condition.

We can see the difference between a horse that is well-fed and one that is
starving because the former is sleek and smooth. On the latter the ribs
stick out and the coat is dull.  There are many other things we can observe
about a horse that allow us to deduce information about its age and
condition.

Bees are no different in that respect, but they have an exoskeleton, so we
can't expect to see ribs showing.  They are also built very differently
from us, so the familiar clues that will tell us a lot about the state of
our fellow mammals may not apply.  Nonetheless, there are many obvious
signs, such as the condition of the bee's hair and condition of the wings,
and the size of the bee and its proportions compared to others nearby.

There are other more subtle cues too, that become obvious to the persistent
bee lover, but the largest problem we face is that bees are sufficiently
small that many us -- even those of us who are legal to drive and can read
without lenses --  cannot see them clearly without reading glasses or some
other aid like a jeweller's loup.

allen
http://www.internode.net/honeybee/diary/