Are Jains vegans

Answer 1

Not necessarily, though many are. It is not required, but it would be indubitably hypocritical for a Jain not to be vegan.

The answer is complicated, and is equatable to this question, "Can I be Catholic and also be prochoice and believe in divorce?" That would violate some of Catholicism's central principles, but if that hypothetical person says they are Catholic there is not much anyone could (or should) do about it. Religion is personal and can only be followed as that individual sees as best fit.

The central tenet of Jainism is ahimsa, or nonviolence. To support the slaughter and exploitation of animals, which one is invariably doing if not vegan, would be violating everything Jainism stands for. Some Jains are even fruitarians. Many will brush paths clear before walking, to prevent killing insects. Some refuse to drive because of the insects that will be killed on impact with the windshield.

Answer 2

• Yes, followers of the Jain religion are lacto-vegetarian. That means that, of the animal kingdom, only dairy products and honey are allowed.
  
  Strictly speaking, even underground roots (such as onion, potato, garlic) are not eaten by those who follow the religion strictly. They are considered foods that arouse negative passions.
  
  
• Most Jains do not eat honey, as gathering honey harms the community of bees. Also, the reason for not eating root vegetables is (1) digging them up can harm organisms in the soil or (2) it kills the entire plant (I've seen both explanations and don't know which is correct).
  
  Some other things (some spices, alcohol) are forbidden because they arouse negative passions.