Why Does a Venus Flytrap Eat Insects?


The Venus Flytrap is a carnivorous plant that grows in the coastal bogs of North and South Carolina. Most plants get their nutrients from the soil, but the boggy soil in which Venus Flytraps grow is low in nutrients, specifically nitrogen, so carnivorous plants need nutrients from other sources, such as insects.


Given suitable conditions, bacteria in the soil convert nitrogen into a form plants can use. Flytraps grow in soil too acidic for the bacteria to do this effectively.


Carnivorous plants (specifically, insectivorous), like the Venus Flytrap, prey on grasshoppers, flies, snails, slugs and spiders to get the nutrients that the soil lacks. Caterpillar's can turn the tables on the Fly Trap by eating their way out of its trap.

Plants and Nitrogen

All plants need nitrogen for growth and development, to make chlorophyll and proteins and to help roots absorb water and nutrients.

Insects as a Source of Nitrogen

The Venus Flytrap gets the nitrogen it needs from the amino acids in the tissue proteins of its prey. The nitrogen is made available by the process of digestion and is absorbed by the walls of its trap.


Digestion is accomplished in this insect-eating plant by the secretion of digestive juices and formic acid from the trap walls. The formic acid is an antibiotic, preventing the spoilage of the prey before it can be absorbed.


  • "Carnivorous Plants of the World;" James and Patricia Pietropaolo; 1986
  • Carnivorous Plants
  • Nitrogen in the Plant

Who Can Help

  • The Carnivorous Plant Society
  • Botanical Society of America
  • Venus Fly Trap video
Keywords: Venus Flytrap, Carnivorous plants, Insectivorous Plants, Insect Eating Plants

About this Author

Lyle Berg is a Marine Biologist with a B.S. degree from the University of California and specializes in marine mammals. Lyle has worked with dolphins, California sea lions, Stellar Sea Lions and sharks. He has been writing for three years. His science articles have appeared in “Highlights Magazine.”