Aggressive over a sweet treat?

Question
I have a 3 month old female ferret. I've had her about 3 weeks now and she been a great addition to our family. She has never bit anyone, she very happy and healthy. The other day we were lounging watching movies and I had some candy out (orange slices, to be exact) Well my dear ferret grabbed one and took off like you wouldn't believe. I've been told sweets are bad for them and I thought the sticky chewy candy would get stuck in her teeth so I tried to take it away. She wasn't about to let me take it. She barked, hissed, and made as much noise as possible without opening her mouth far enough to drop it. She was truly aggressive and tried bitting but wasn't going to drop the treat. I was shocked and even a little afraid! She has never done anything even close to this. What's going on? Also, I thought ferrets don't like sweets?  

Answer
She doesn't have to like sweets (although I am not sure that is a true statement) to steal something, she just has to want it.  She is acting like a perfectly normal ferret that has decided something is of high value.  You should see mine fight over a mouse.  Don't worry about the behavior and next time she takes something she shouldn't have, watch where she goes to hide it then take it back - just make sure to exchange it for something she likes just as well or even better.