Hamster behaving strangely

[cestsquish]

Hello,
I've had my dwarf Russian hamster for almost 5 months and she's always been very sociable, she used to wake up at about 8pm and would love to be handled and played with and go to bed about 7am. But for the last few weeks she wakes up at 10pm and 11am, isn't interested in being handled because she's just woken up and she's also completely rearranged her cage. Her cage has three floors and in the base under the first floor theres a bendy wooden bridge she used to nest in because it was dark, she then moved to sleeping next to it under a pile of bedding and in the last few days she's pushed her bedding up one end of the cage and sleeps next to her flying saucer which is a very light place which seems like an odd thing to do. When we first got my cat she was nervous for a few days and since then she's not bothered by him and would happily come out and run around, they've met nose to nose and when we've had her in her ball she'll chase him while she's in it so I don't think the cat is causing her weird behavior, the other thing I can think of is it's going into summer here so it's getting lighter so I don't know if that would be the reason for her weird behaviour? I'm just worried as I don't get to handle her often at the moment because she wakes up as I go to bed and I'm concerned she'll be under socialised as she's on her own in there and I don't know if I should try and change her sleeping pattern by calling her awake or something? Help!

[cypher]

Whether you think she is stressed or not having your hamster running around in the ball with the cat in the same room is just asking for a horrible accident to happen one day I'm afraid.
Balls really aren't suitable for dwarf hamsters anyway so you would do much better to either buy or make a play pen & interact with her that way, you would also be able to observe her behaviour much better & see if anything was wrong, at least keep the cat out of the room whenever she's out of the cage & preferably at all times.
While changing routines & sleeping places can be perfectly normal dhanges in behaviour can also be a sign of stress or ill health so it may be that the cat is stressing her & she isn't happy with her out of cage time so is hiding away, it could be that there is something wrong health wise too so give her a full health check.
If you have a high cage with lots of levels rather than plenty of floor space she may not be too happy in there & might do better in a different cage.