The lid has 3 magnetic clasps so that holds the lid down. It also has 2 lockable clasps on both sides so even i could not get out.
As for the fan, why not. Seemed like a good idea at time. The fan is just to regulate humidity and temp in case it's not regular. I don't know realy saw one in a picture. Old chinese proverb say...''Better to have a fan and not need it than need a fan and not have it''.
I'll also put a bambo climbing frame in the warm side.
My own home cost less to buy and run than this thing.
I already have an aprox 9 month old corn who will be transfered as soon as my e-bay thermostat arrives. I put him in for litttle periods of time already but do not want to leave him in for too long without a thermostat. Should be up and running in a week.