I have one of the mesh tops, and it has held my BP in well. It is a special one that locks on really well, and i axidentally stepped on it, so it is slightly warped, but in a good way, it locks on even better now. haha. I would say, go to Petsmart, and see if they have one of the locking tops, and if they dont, get some clips to secure it. Also, scince i like to keep my room pretty hippie, i have a heavy candle on one corner (i dont light it, it just has a cool pattern on it), and a clay bottle that says love on the other, he presses the cage top all the time. He has never gotten out though.