I don't know if these links will work but I could really use some advice, please! New syrian hamster for DD arrived yesterday, and we bought this rotastak cage www.amazon.co.uk/Rotastak-Small-Animal-Housing-Tunnel/dp/B002RBKWBC/ref=sr_1_4?s=pet-supplies&ie=UTF8&qid=1360527794&sr=1-4.Problem is the tunnels seem tight to me even though it is still young, the insides are smooth with no grip and no ventilation. I've looked at these tunnels: these but the one Amazon review says they are too small! Please could anyone with more experience of Syrian hamsters than me give me some advice? DD and I are happy to buy whatever pebbles needs, and I am worried that the tubes I have are not really suitable. Does anyone have anything better they could recommend, please? TIA