>Every night he has his "fidget mode" right before he goes to sleep,
>during which he goes from digging at the couch, to digging at the carpet,
>back and forth, pacing and looking for something to destroy. I usually
>respond with 1 or 2 corrections, but then I crate him. He goes into the
>crate, and scratches and chews at his bedding and whines (like throwing a
>tantrum) and then crashes. Then i let him out once he's calm, and he does fine
>through the night. He does this every night regardless of
>the fact that he's been thoroughly exercised and had a training session.

>He even does this when I'm at home, but in another room, or even on the phone.
>Its almost like he does it for attention, but he knows he'll be crated if
>he keeps it up. I've never rewarded him for bad behavior, either.

Based on the limited information you provided, it is very difficult to make recommendations. It APPEARS your dog's behavior is triggered by a specific event ("bed time") or anticipation of a specific event (crating, separation (or bed time as a kind of separation/anxiety period), etc.)) It also appears that his anxiety reaction (destructiveness) "supercedes" his desire to please his master (assuming he recognizes you as his master/alpha) or his desire to avoid correction (assuming he perceives your (hopefully quick and well timed) corrections as correction rather than a way of getting of attention).

The dog should not associate crating with being punished. If you are using it this way it is highly likely the dog perceives it as such. It is unclear whether this perception adds to his anxiety prior to crating.

It also may not be helping that the other dog is not similarly treated /"punished", thus arousing jealousy and possible resentment.

Based on the above:

(1) I would attempt to make bed time a special and happy event for your dog. A time for receiving treats, special (ALWAYS earned) praise, etc. Some owners allow their dog's to sleep with them. In your case this "solution" may be good or bad. It would be bad if the more underlying problem is that your dog does not perceive you as alpha (see below).

(2) I would avoid situational nighttime crating if possible, though I would provide an open crate in case the dog chose to go in. I would have the dog's toys out as well. If this means you will have to be alert and monitor your dog's behavior for a few nights, then so be it.

(3) I would reinforce your role as alpha through continual use of the standard obedience commands throughout the day, particularly "down", "stay", "come", "place", etc. Generous praise should be used provided he obeys instantly on the first command. It is important when giving praise to use the tone of your voice to convey how proud you are of your dog. If you and your dog can not perform the aforementioned basic commands quickly and correctly then formal obedience training or purchase/reference to a a good book on dogs and dog training such as "Good Owners, Great Dogs" by Brian Kilcommons would be helpful.

(4) I would take special pains to make sure that both dogs believe they are equally loved, etc. I would also avoid speaking about how "childish" you dog is to other people in front of your dog. Believe it or not, dogs can pick up on this.

Final Note: There is nothing wrong with safe crating, whether for a dog of two or ten. However, in my opinion, crating should not be used as a crutch or as punishment. I am assuming that your dog can be "safely" left in the house during the day and only rarely becomes destructive. If this is NOT so, then he has more "classic" case of separation anxiety. The following is an excerpt form an earlier post on separation anxiety:

The key is to acclimate your dog to increasing periods of separation. You will need to start separation exercises involving periods of well less than one minute and gradually increase to a few minutes, etc. Leaving her an article of clothing with your scent may also help. You do not want to make such a big deal of your comings or goings that she anticipates the "dreaded" event and gets more anxious. Comings and goings should be treated as ordinary events. Babying her is an absolute NO. Punishment won't help. SAFE crating may also help relieve anxiety and protect her from the consequences of her destructiveness. If you go on a long trip board her or when you return she may be worse than when you left.

CONTINUALLY reinforced obedience training and play that develops focus and concentration will help. It will give her structure and reinforce your control. She, in turn, will learn to control her impulses in the face of a variety of environmental stimuli (distractions). Exercise may also help. As your dog becomes more acclimated to her home and family she will gain confidence and may, with the right reinforcement, embrace change... New Fun, that is.