Using damp sheds from males and females can sometimes spur reluctant breeders into action. If you have animals that are breeding well, save their sheds! I like to mist the sheds slightly so that they are a little "stinky" and put them into a cage with a pair that isn't doing much breeding wise. I'll try male sheds and female sheds and usually see good results with this method.
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Swap the bedding from a female that is breeding with a female that isn't. This one is a lot like the shed trick above, but again, do what you have to do in order to get those pairs locked up! I like to think that the smell of "snake sex" from the bedding of the female that was breeding gets the reluctant breeder to wake up and "smell" the roses.
from www.8ballpythons.com