She Is Naughty!!

[ImogenesMom]

Sounds perfectly normal to me. Imogene, my Syrian, is an inveterate water bottle climber -- especially when she's in estrus as she's sure that she can find a way out above the bottle to go look for boy hams! She also loves to dig down into the corners of her bin, then execute a flip-turn and head in off in a different direction.

[flowerfairy]

Kashi is my only girl syrian and is a real whizzer about and chewer. She has loads of cardboard boxes and paper bags with food hidden in them to try and interest her.

She is in a similar sized cage to your hamster and has two wheels, a silent runner and a junior wodent wheel (small but she adores it).

So, sounds normal hamster behaviour to me too. Never heard of a cage liner. Sounds like its not necessary from what others are saying.

She does look rather cute balanced on her water bottle!

[DrropS]

My hamster is doing the same with corners. Daisy keeps digging in a corner for while, but she's just telling me it's time to get out of the cage and explore the room.
After she has been out of a cage for about 1,5h-2h she's completely happy and start doing other hamster stuff.