I was browsing around for potato recipes and randomly happened upon a site that listed vegan friendly beers, and some were classified as not being vegan friendly for containing honey. Seriously? How is harvesting honey harmful to the bees? Is it because they're in captivity? They're insects, so it isn't like they're even aware of it. I can respect veganism, but extending it to insects just seems totally unnecessary and excessive. I assume vegans bathe and wash their hands, right? Doing so kills bacteria and other microbes, so where is the line drawn?
The definition of a vegan is one who does not use any animal-derived products.
Vegans have different reasons for choosing their lifestyle. Some do it for ethical reasons, some for environmental reasons, some for aesthetic reasons, some for proposed health reasons, and many for a variety of reasons. Vegans avoid honey because honey comes from bees, and bees are animals. Many vegans may believe that the bee can suffer in some way, while others may feel that they do not, but they still don't want the honey.
The line may be drawn at a variety of places for a variety of reasons, depending on whether one is a partial vegetarian, full vegetarian, vegan, or something else. For many vegans, the line is drawn at the edge of the animal kingdom.