I got this cage for my two pet rats, who are both babies (5 weeks), and so far I love it! This cage is huge! Far too big for my rats right now, but I'm glad that they have lots of room to grow into. The bars are also close enough together that they can't squeeze through. However, there is a large gap on each side of the plastic tray at the bottom. I did have one escape that way, and now I have a box underneath that holds the tray up so that the gap is small and baby rat-proof. Overall, the cage's construction was easy, although I struggled a little with the three levels (I basically wrestled them into place, but I'm sure that not everyone will have the same approach or trouble I did), and the resulting structure is very sturdy. For the price, this cage is perfect!