Question

Pitcher plant and Venus flytrap are green plants and synthesis their food,then,why do they kill insects?

Answer 1

These plants (e.g. pitcher plant) are green and carry out photosynthesis to obtain a part of the food required by them. But they do not get the nitrogen from the soil in which they grow. So, insectivorous or carnivorous plants feed on insects to obtain the nitrogen needed for their growth.