jeremyc,
Snakes go off feed every now and then, ussually it is not a cause for concern. I do have a couple of questions for you though,
How old/big is the snake? It is possible if mature that it is looking to breed. Important here is if the snake if female, she might have produced eggs in anticipation of finding a mate. Most females re-absorb infertile eggs np, but some lay "slugs". If this is the case and she cannot pass them, she needs to see a vet.
What are the temp and humidity levels? If they are off the snake may be uncomfortable, not ready to eat and trying to find a better place to be. This is the #1 reason most snakes change behavior like this. Check them out to be sure, with guages, don't guess.
Does your snake have mites?This is another all to common cause of this type of behavior.
When was the last bowel movement? If your snake hasn't dumped in awhile it may be constipated. You can check for this as well as eggs by gently feeling around the lower third part of it's body, just forward of the cloaca. If you feel any masses, you may try to relieve it by filling the tub partway with warm water ( around 85 F or so) and letting the snake swim a bit. If that doesn't work a trip to the vet is in order.
Have you changed anything, or added any new animals right before this started? A new addition, especially to his/her cage may have stressed it out.
Good luck,
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Drew Z.
Member, NJHS