I shouldn't be surprised, but the company I work for is going to start carrying frass. It is insect poop. If you are choosing to garden veganically, you might want to avoid it if you adhere to abstaining from insect by products as well. I love using bugs and worms beneficially, but I really question how the frass is harvested, especially since many insects use their frass to build their homes!http://insects.about.com/od/insects101/a/bugpoop.htm
So, when buying your ferts and nutes, check the ingredients for this if you care about that sort of thing.