Insectivorous plants like Venus fly trap generally grow in low marshy areas where the nutrient especially nitrogen content is very less and the quality of soil is poor. Though they have chlorophyll to perform photosynthesis, they fulfil the requirements of nutrients of their body by consuming insects. The flaps of the trap are nothing but its leaves that close when an insect comes inside and gets stuck to the sticky hairs present between the leaves.trap the insects and digest them by secreting some enzymes and obtain the nutrients from their body.
Regards.