Why does a Venus flytrap catch insects?
Its trapping leaves help this plant grow where the soil supplies few nutrients.
The short answer
A Venus flytrap catches small animals for extra nutrients because its native soil is poor in them. Like other green plants, it still gets its energy mainly by using sunlight.
Equal-sized Puschel and Flauschi stand beside a potted Venus flytrap in a botanical garden. The illustration simplifies leaf shapes. The additional diagram is a model; its stages take different amounts of time. AI-created illustration, not a photograph of nature.
What the diagram shows
The diagram simplifies the process. First compare its shapes and arrows. You can read its labels in larger text below.
Read the picture labels
These are the words and sentences from the diagram above. The full explanation follows below.
- From touch to extra nutrients
- 1 · Touch
- Trigger hairs respond.
- 2 · Closing
- Two leaf halves.
- 3 · Digestion
- Takes several days.
- Suitable further signals lead to digestion. Not every trap contains prey. The plant still needs light and water. Diagram, not actual sizes.
An imagined Wusel scene
Puschel and Flauschi investigate
Puschel places a fly over the Sun on his plant chart. Flauschi asks whether the plant no longer needs light. They compare the two routes in the model. He moves the fly to nutrients and leaves the Sun as the energy source.
Look closely
Find an open trapping leaf and the bristles along its edges. These leaves are not flowers. The diagram below separates touching, closing and slow digestion.
An example to help you understand
Fold a large green sheet of paper in half. Its two sides resemble a trapping leaf. Open and close them. This is only a model of the shape: the paper has no trigger hairs or digestive substances. A real plant moves its leaf without paws! Explain with the model and leave real traps alone.
Try explaining it
What extra supply does a Venus flytrap get from prey?
Choose a), b) or c), then explain your choice.
- a)The sugar other plants make using light.
- b)Water to replace uptake through the roots.
- c)Nutrients; it still needs light.
Show the explanation
Correct: c): Nutrients; it still needs light.
A Venus flytrap catches small animals for extra nutrients because its native soil is poor in them. Like other green plants, it still gets its energy mainly by using sunlight.
Word help
- carbon dioxide
- A gas produced, among other ways, by working body cells and breathed out.
- nutrient
- A substance a living thing needs to live and grow.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
1. Plants need different materials
Venus flytraps come from a small area of North and South Carolina in the USA. They grow in wet soils with few nutrients: substances living things need for growth and body functions. This plant obtains some nutrients from small animals too. It does not chase them. Specially adapted leaves catch them.
2. A leaf responds to touch
Each trap has two halves with tiny trigger hairs inside. A suitable sequence of touches, usually two within about twenty seconds, can cause it to snap shut. One hair may be touched twice, or different hairs may be touched. This helps prevent every single accidental touch from closing a trap. The structures along the edges are plant bristles, not teeth.
3. Prey provides extra nutrients
If a trapped animal keeps moving and stimulates the hairs again, the leaf can close more tightly and release digestive substances. These include enzymes, substances that help break other substances down. The plant absorbs nutrients from its prey over several days. Not every closed trap contains suitable prey, and not every touch leads to digestion.
4. The plant still needs light
A Venus flytrap also makes sugar using light. This is photosynthesis. It uses water and carbon dioxide, a gas in the air. Sugar supplies energy and material for building the plant. Insects do not replace sunlight or water. Think of sugar and extra nutrients as different building materials: the plant needs both for different jobs.
An optional question for further exploration
You can use the longer explanation above. This is extra, not needed for the first quiz.
An extra question
Could a Venus flytrap grow without light if it caught enough insects? Explain what prey supplies and what it does not replace.
Discover the answer
Prey provides extra nutrients that may be scarce in the soil. It does not replace the light needed for photosynthesis, which makes sugar. Venus flytraps still need suitable light and water.
Pictures and sources for adults
Sources for further reading
Facts checked against the specialist sources below on 12 October 2026. The Wusel scene is fictional; comparisons and simplified models are explicitly explained. Sources are in English.