Hamster bored with toys?

[randomthing42]

My hamster was finally fully tamed after like 2months at half-term and since then she and I have had a lot of fun exploring the different sofas and beds in the house. The slight problem is no matter how long she is outside the cage, she always wants to explore more and will bar-chew to try and get my attention for a few mins but when we ignore her she walks off and seems fairly bored. Her cage is 80x50 and I change her toys every week between the ones we have (see-saw, climbing house thing, tunnel, small kong and different shaped toilet tubes) but she still seems just not particularly interested, any suggestions on what toys we could get that will stimulate her and help her not want to be exploring outside the cage all the time. She has a sand bath, a large level and a 12" wheel (shes a big girl xD). I am going to get a playpen soon but I probably need more toys first.