So I did some Googling and apparently some tiger moths are poisonous. They don't produce the poison, but ingest it when they are larvae. Because tiger moths are nocturnal and their primary predators are bats - which hunt by sound - the moths emit sounds that warn the bats not to eat them. Note: My aunt is still retarded.
This makes up for the time I saw him on Halloween at the Easton State Theater many years back and he was so messed up he could only do about 15 minutes of material.