We're been working on crate stuff. I hadn't used any hardware on his crate at all for several weeks, with no problems. I was delayed one day when house sitting and he pulled his crate open while I was out, but didn't destroy anything (thankfully!!), so when I noticed that he was pulling the "safety" apart on the one end of the crate, I put one padlock on each end. If I'm going out and think he's likely to be worried, I clip a bolt snap to the door for added security, but I think it's probably unnecessary. His overall crate anxiety has gone WAY down.