Soft tissue within small insect heads are hard to investigate. Muscles, glands and the brain are accessible by opening the head or cutting the head into thin slices.
I produced a chemical procedure that makes the surface of small insect heads durable for confocal laser-scanning microscopy (CLSM). Thus, I was able to scan whole insect heads and reconstruct soft tissue, like glands and individual neuropiles.
I also used fluorescent dyes for backfills, which appeared to work with this procedure.