Catherine, I saved cardboard boxes up for weeks and weeks, and used those to block off Chewy unfriendly areas of my flat, and he STILL wanted to get in them. He must have had about 20 foot by 15 foot to run around!
But I'd recommend saving bits and bats to block areas off or to make a cardboard playpen, it's a nice bit of a treat and change from time to time
I don't think those leads for hamsters are suitable at all
. Lucky very few places sell them, so you don't see tons of children buying them! Much too stressful for the wee chaps. x