[Sharkie]

I've had Winnie for about a week now. At first she really loved playing on her wheel (she'd do it for hours at a time!) but in the last couple of days I've noticed that she has been chewing on her bars at night, and not paying much attention to her wheel or other toys.

I've tried to provide her with lots to gnaw on (wood sticks/gnawing toys, nutty chew sticks).
I've also read that bar chewing can mean that a hamster wants to come out to play more. She's not fully tamed yet (she will sit on my hand, but is still a bit scared of me) so I'm not that confident with letting her explore yet. I tried letting her play in a wire pen that i have, but she just seemed really quite nervous and intent on escaping.

Basically, are there any other reasons why she might be chewing the bars/what can I do about it?