[jraph]

From what I understand, Jains are lacto-vegetarian [1]. Vegans draw that line further (because they also don't take milk).

As a human being, if you avoid eating plants, or things that eat plants, you die.

[1] https://en.wikipedia.org/wiki/Jainism

[dr_dshiv]

Jains don’t eat foods like onions and potatoes. But, so far as I know, this is on account of the bugs that may be harmed when harvesting soil-based plants.

[pests]

I believe it's also as the onion or potatoe is the entire plant and when you eat it, it's gone. Verses eating a strawberry or Apple does not destroy the plant.