Really? LOL.....
I have Dojo's in my 55G, and I've never covered my top. And they haven't even tried to escape yet. If I put the glass tops on, the water eventually gets too hot, due to it being hot here. Stays at 82 degrees with the tops off, but gains 2 degrees a day if I have the tops on.
The majority of the time mine loves burying itself in my pool filter sand that I have in the bottom. Sometimes the only thing you can see is his eyes sticking above the sand, eveything else is buried.