A vegan diet should not include any products that are derived from or produced by animals. Animals are killed to obtain meat and many other products. Moreover, the Vegan way of life does not allow dairy products, egg and honey as a part of the diet because they are produced by animals.
 
Although eggs are not obtained by killing animals, commercial poultry farming involves many cruel practices that put them through a hard time, mostly throughout their lives. Hens are kept in small battery cages that hardly have enough space for them to move around.
 
In commercial cattle farming, the cows are impregnated every year to maximize milk production and the calves are mostly sent to slaughterhouses when they are a few days to weeks old. All of these are pointed out by vegans as reasons for why they do not take dairy products.
 
Honey is also not vegan because commercial bee farming harvests the honey that is the natural source of nutrition for the bees and replaces it with sucrose that has low nutrient content.