How do kittens avoid squabbling when feeding from the mother?

 

Within a few days of birth each kitten has developed an attachment to its own personal nipple, which it recognizes with ease. Amazing as it may sound, this is possible because each nipple has a special smell.
We know this because if the belly region of the mother cat is washed by her human owner, so that it is cleansed of its natural fragrance, the kittens fail to find their favourite nipples. Instead of peacefully taking up their usual stations, they become disorientated. Confusion reigns and squabbling occurs.
It is remarkable to think that in the 'simple' world of the very young kitten there is odour detection based on differences so subtle that they can label each nipple as clearly as name-cards on school lockers, and that in this way orderly sharing can be maintained at feeding time.