Hi, first time gerbil owner here, just got 2 females at the weekend. I've got one of the smaller savic gerbil cages, and I'm already thinking I might need to upgrade. It doesn't seem big enough, once the house is in there etc. And the girls keep chucking shavings out of the bars all over the floor. I'm wondering if a glass tank is better. Can anyone advise? The downside of a glass tank that I can think of might be that it's more difficult to have to take the whole lid off rather than open a small door sometimes. And you can't put your fingers to the bars for them to sniff or take a treat, which might be worse from my daughters perspective.