Dallas, I have always admired your set up, even I remember when you first posted a picture of it, but it was from a different angle. Lovely.
RDY-B you have some very good points.
Richard, another way if you would wish to prevent drifting would be to make a symbol on the front of each one, a different shape, for example. But remember if you decide to do a symbol like a "diamond" and a "square", a diamond is just a square turned sideways ;) ;) :). You can do anything to make a hive look different than another one. Bees orient to the position of their home, no matter what.
Sometimes you will notice on a nice warm day, in the afternoon usually, hundreds of bees hovering around the front of their colony. They will be hovering, floating (whatever you may call it) backwards, looking at their home. They are performing their orientation flight. This ensures that in the next few days when they are leaving their hive to take on foraging duties, they will know what their home looks like and the where it is located. After a few minutes they will go back inside. They may do this a couple of times a day for a couple of days. When you witness this marvel of nature, you will see what I mean. It can sometimes look overwhelming and it may cause concern, but if you hang around even for a few minutes more, you will see the numbers decrease dramatically, the orientation flight is over. So cool.....
Bees perform their orientation flights (obviously) when they are just about old enough to leave the hive and leave behind the former duties that they were involved in. (Older bees, if need arises, can re-assume the duties that they undertook inside their colony too). The age-related tasks of the honeybees are a marvel in themselves. That is a very good part of the biology of the honeybee to understand and study, and it is interesting too.
When I was on vacation this summer to a wedding across the other side of my country, I spent great deal of time typing out some very interesting data from a book that I have read twice now. This book was written by Mark Winston, The Biology of the Honeybee. Very deep book, but a very good book to read. If you are interested, I could PM you the part of this book on the Aged Related Tasks of the Honeybee that I typed. It would be my pleasure to do so and it is some very interesting reading :) :) :)
Wow, sometimes I just don't know what happens to me, I get to ramblin' and get rather carried away with longish posts :) ;) Have a wonderful and beautiful day, Cindi.