Please try this out and let me know what happens.  Take a ferret, any
ferret, and hold them in both hands with their stomach facing up and your
hands on there shoulders and butt.  Rock them back and forth about one to
two feet, and holding them about a foot from your chest.
 
My friend came over and started doing this to one of my ferrets and it was
incredible.  She went from complete hyper-activity to a coma like state in
about one minute of rocking.  She was yawning and perfectly content in a
semi-stranger's hands.  I had never seen anything like it.  So we tried it
with the other ferret and got the same results.  They seemed to get
disoriented slightly from the rocking and just fall asleep like babies.  I
am interested to see if it happens with other ferrets or just my two sisters.
[Posted in FML issue 1643]