My Doodlebug is about 4 1/2 months old and I have caught him chewing on the corner of my hallway RIGHT IN FRONT OF ME and know he also chewed a spot on the drywall were our bathroom door should be (we're remodeling). I'm pretty sure they are both teething and are not neurotic psycho pupster.
I think you just need to keep him busy with something like a kong. They are like little kids, if you take your eyes of them for a second they are into something to entertain themselves ie crayons on the walls.
I remember those days well.