Does a carnivorous plant need carbon dioide?

Yes, carnivorous plants do need carbon dioxide (CO2) for photosynthesis, just like other plants. While they obtain nutrients from trapping and digesting insects, they still rely on CO2 from the environment to produce energy and grow. The ability to capture prey helps supplement their nutrient intake, particularly in nutrient-poor habitats, but they still require CO2 for overall health and functioning.