The kaytee one has no air holes, but so far, i see no fogging up inside that one. It's spacious and fun even for two critters.

Great habitat for mice hamsters and gerbils.

The pieces are easy to disassemble and put back together again. This goes by pretty quickly and cleans out all of the pee an poo in one go.

The design keeps our hamster's bedding (and poop! Safe.

This also comes with a nifty 5-way cube connector. It has locking rings which are awesome. Having both sides flush against the unlocked ring is key to getting it locked on.

The latch on the back of the cage is difficult to latch. The cage needs to be disassembled to clean it, and the tubes must be taken apart and scrubbed with a toothbrush if your hammy happens to pee in one.

Everytime my hamster trying to climb, it falls hardly. Nothing locks in place unless you use duck tape.

Everything about this habitat is flimsy and difficult to assemble. The lower left portion of the ovo has a gaping hole - which i had to plug with whatever i had on hand. Each connector is a struggle to lock.

After a few weeks of use, the weight of the water comes in to play and causes some issues with the sturdiness of the habitat. The water bottle leaks. It is also very poorly ventilated.