What did Michael sander send to the draft board in Ohio?

Sander sent the draft board body lice.

I remember Mitchell Sanders sitting quietly in the shade of an old banyan tree. He was using a thumbnail to pry off the body lice, working slowly, carefully depositing the lice in a blue USO envelope. His eyes were tired. It had been a long two weeks in the bush. After an hour or so he sealed up the envelope, wrote FREE in the upper right-hand corner, and addressed it to his draft board in Ohio.