I like to think that most of us are honest people, but I’ve had local people come by with gliders they were told were 8 weeks old and because of my experience, I can tell they are really only 4-5 weeks old.  If you get gliders too young, the risk of them dying on you early is greatly increased.  So here are some general guidelines that should apply in most cases. 

If you have an average sized hand, the body length (not including the tail) should be about the width of your hand, or slightly longer.  If the body is smaller than the width of your hand, that baby may be too young.  Also, the hair on the tail should be fluffy and full.  If the fur is laying somewhat flat on the tail, that baby is definitely too young.  Tails start getting pretty fluffy around 6 weeks out of pouch age, so flat tail hair is a sure sign the joey is too young to be leaving home.