My hamster keeps trying to get out of his cage?

[angel]

There's a gap in my hamsters cage to let the spout of the water bottle through and when she's awake she bites at the water bottle for ages trying to get it out of the way so she can get through the gap. She's only started this lately. I thought maybe it was boredom and wanting out for a run? She only wakes up when I'm asleep usually so it's very hard to let her have a run around in her ball if she wants to at 4 in the morning! I try to put her in it the minute I see her awake and moving about but like I said sometimes she isn't up while I'm awake. Should I just start waking her up in the late evening and putting her in her ball so that she is getting enough stimulation? And is there anything I could put on the bit where she bites to stop her doing it? Preferably something that's easy to get the hold of.

She does have toys and chew toys and a wheel in her cage at the minute just in case anyone suggested that

Thanks for your help!