I had to laugh when I read about the requirement "to let the animals take
natural sleeping positions". For my ferrets, natural positions include:
 
* with head hanging over the edge of the hammock so that the blood all rushes
  to the nose
* with head between the hind legs
* in a U shape, with feet sticking in the air
* bent in half, with one half rotated 180 degrees from the other
* with large ferret smothering small ferret
* with small ferret resting head on stomach of large ferret. Small ferret's
head bobs up and down in rhythm with large ferret's breathing.
 
I'm sure others can think of other uncomfortable sleeping positions that our
fuzzies consider "natural".
 
Linda, Richard, Joy, Belle (the small ferret) and Caruso (the large ferret)
[Posted in FML issue 1406]