Has anyone ever had snakes escape from their rack? Or ever hear of anyone having an escapee from a rack?

I'm getting my snakes tomorrow and I just started to get paranoid that they will somehow escape from my rack. Most of the 28qt tubs fit pretty well and the 41qt tubs are extremely snug. Do snakes ever try to push their body weight against something to push it open? I had a snake once push through the lid of her tank, but never up against the side.

Anyway, I get paranoid about everything and after how hard I've worked on all this, I would hate for a snake to get loose.

Here is a picture of my rack (I posted this earlier)




Anyone see any safety precautions I should take?

Thanks.