Nature · 2
What is the purpose of the Venus flytrap's roughly 20-second window between the first and second trigger-hair touch?
Answer
To confirm that live prey — not debris or raindrops — is present before closing
The Venus flytrap requires two touches within about 20 seconds because a single brief contact could be caused by a raindrop or windblown debris. A second touch within that window strongly indicates a moving, living insect, ensuring the plant only expends the energy of closing and digesting when it is likely to capture actual prey.
💡 Did you know?
Venus flytraps count prey touches: one triggers reflex, but trap only closes after two touches within 20 seconds—preventing false alarms.
Other options people guess
- To allow digestive enzymes to begin flowing into the trap before it seals
- To give smaller insects time to escape so only larger, more nutritious prey are caught
- To charge the electrical potential in the trap cells to a level strong enough to snap shut
Topics
- venus-flytrap
- carnivorous-plants
- plant-biology
- adaptation
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