It has been a drought year so it probably wasn't pollinated properly. Do you have a picture? My sweet corn had a good bit of missing kernels on some ears this year.
Glad to hear your hubby is doing better!
Try a 5-gallon bucket half-full of water. Then throw sunflower seeds all across the top-they will float. Put a narrow board across the top of the bucket to "help" the mice reach the seeds better. I have never tried this-we don't have a mouse problem, but...