It's no secret that casinos have quite a few tricks up their sleeves. Here are some that they don't want you to know about.

Casinos control everything from their carpeting to their windows to their air conditioning settings. The whole point is to keep you gambling as long as possible, for as much money as possible, and with as few distractions as they can account for. But while plenty of their schemes are clearly visible, there are other happenings going on behind the scenes that the general public doesn't see. For example, did you know that many casinos have completely separate VIP areas for the high rollers? I'm sure you did, but did you know that many have cities of underground tunnels and passageways, up to 5,000 rooms big? One former casino employee even claimed that Las Vegas homeless find their way into these tunnel systems and live in them for years before ever being found out. 

On a different note, if you're an employee, you better be on your game. Security cameras are high definition, and they'll know immediately if your badge isn't displayed, or if you're up to no good. And if you have a shady past, you're not getting a job there to begin with. Under no circumstances will casinos allow their employees to become addicts themselves.