Jains generally avoid lentils, beans, and pulses because they are believed to contain or support many small living beings and involve more violence in cultivation and preparation than simpler foods.

Main reasons:

• More jiva involvement: Many legumes are considered to have a higher degree of life activity than foods like grains, fruits, or milk.
• Rooted in ahimsa: Jainism puts strong emphasis on non-violence. Food choices are made to reduce harm to living beings as much as possible.
• Fermentation and spoilage risk: Some lentils and pulses may be more likely to cause increased biological activity or are associated with food practices that are seen as less pure in Jain diet discipline.
• Traditional dietary discipline: Many Jain communities keep a very strict vegetarian diet, and some avoid specific pulses depending on custom and lineage.

Important note: This is not true in exactly the same way for all Jains. Dietary observance can vary by sect, region, and family tradition. Some Jains avoid only certain lentils, while others avoid all pulses.

In simple terms: Jains avoid lentils mainly to follow ahimsa and minimize harm to living beings.