Of course I don't want the mechanisms to show, so I have to put most of it inside the ears themselves. The servomechanisms are simple -- I made some longer levels from servo horns connected with small screws. Then I inserted that into the ear through a small hole that was helpfully left in it:

I initially planned to secure them by sewing, but I couldn't be bothered to find my needle, so I just secured the servo horns with more of the small screws:

I might remove them later and replace with some stitches after all.

Next, programming. I found a Pololu Mini IMU 9 in a drawer, so I guess that's what I'm going to use for the accelerometer. I found some example programs in the documentation, and I'm trying them now. More in the next log.