Did he eat the mouse eventually? Or were you able to get it out?

As for the tail rattling thing. I looked at your previous posts, and it looks like your snake is pretty new. So while i might suggest knocking off the sissy act and just reaching in and doing what you have to do - with a new snake that may be stressed out, i'd wait a little longer and just chalk up the odd behavior to the stress of a new home. If he's doing the same behavior in a month or two, i'd just reach in...with tongs!

good luck!