Cats nibble at the edge. Drugs in substance? -D

I have two of these cats Beds for 7 months now and my cats are very satisfied.
The shipping was as usual very fast and I have placed the cat bed on my bed,
so I've got my two baby kittens to me when I go to bed.
My cat and my she-cat have the bed of course equal and sniffing for months
nibble both for their life like at the edge of the bed. They treteln, eyes half open and have
purr as only two very happy creatures.
I have developed many adventurous theories to explain this behavior,
but I want to believe that the manufacturer alá Walter White has somehow used the beds for drug transport to
my cats have become dependent through the remains. ;-) Of course, not too seriously.
Aufjedenfall can I recommend this bed warmly and would appreciate feedback of other owners,
were able to observe the similar behavior with their cats.