# Beautiful carnivores

Some leaves snap shut on insects. Others stick them down, let them fall or suck them out of the water. Enter a world where the plant is the predator.

https://mariuscomper.uk/plante-care-vaneaza/en/

A garden with different habits

Some leaves snap shut on insects. Others stick them down, let them fall or suck them out of the water. Enter a world where the plant is the predator.

By Marius Comper · 22 September 2026

It looks like dew. It is glue.

The trap is a leaf. The three small hairs inside each half detect touch.

Noah Elhardt · Photograph · CC BY-SA 2.5 Luc Viatour / Lucnix.be · Photograph · CC BY-SA 3.0

[Photograph](https://commons.wikimedia.org/wiki/File:Venus_Flytrap_showing_trigger_hairs.jpg)

[CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5)

[Luc Viatour / Lucnix.be](https://lucnix.be/)

[Photograph](https://commons.wikimedia.org/wiki/File:Drosera_capensis_Luc_Viatour.jpg)

Start with a touch

## A leaf that remembers.

An insect bends a trigger hair. An electrical signal follows. If another arrives soon enough, the two halves of the leaf snap shut.

Touch twice, less than 20 seconds apart.

The trap is waiting.

An insect bends a trigger hair. An electrical signal follows. If another arrives soon enough, the two halves of the leaf snap shut.

Simplified model: each touch here creates one signal, retained for 20 seconds. In the real plant, the response depends on movement and conditions; a single bend of a hair can produce two signals. Burri et al., 2020 ↗

Closing is just the beginning. The movements of trapped prey can generate further signals that help trigger digestion.

## Why would a plant eat an animal?

For nutrients that are hard to find in the soil. Many carnivorous plants grow in places short of nitrogen and phosphorus. Prey supplies some of these elements; sunlight still provides energy through photosynthesis.

The traps are modified leaves. Flowers retain their role in reproduction. Pavlovič et al., 2014 ↗

Five ways to catch prey

## Not every hunter needs a trap that snaps.

Choose a plant. Look at its leaf and follow what happens to an animal that arrives there.

Dionaea muscipula . Noah Elhardt · Photograph · CC BY-SA 2.5 .

[Photograph](https://commons.wikimedia.org/wiki/File:Venus_Flytrap_showing_trigger_hairs.jpg)

[CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5)

Dionaea muscipula

### A leaf closes around its prey.

Trigger hairs detect movement. Electrical signals set off the rapid closure of the two halves of the trap.

Look closely

The trigger hairs are inside. The long spikes around the edges form the bars of the trap.

Drosera capensis . Luc Viatour / Lucnix.be · Photograph · CC BY-SA 3.0 .

[Luc Viatour / Lucnix.be](https://lucnix.be/)

[Photograph](https://commons.wikimedia.org/wiki/File:Drosera_capensis_Luc_Viatour.jpg)

Drosera capensis

### Those sparkling drops are sticky.

An insect gets stuck in the secretion on the leaf. Glandular tentacles, and in some species the leaf itself, can bend towards the prey.

Look closely

Each drop sits at the tip of a tentacle. The dew-like appearance conceals a sticky surface.

Nepenthes villosa . kallerna · Photograph · CC BY-SA 4.0 .

[Photograph](https://commons.wikimedia.org/wiki/File:Nepenthes_villosa_Mt_Kinabalu_Sabah_Borneo.jpg)

[CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0)

Nepenthes villosa

### A leaf becomes a container.

Prey falls into the liquid inside the pitcher. In many Nepenthes species, the wet rim is extremely slippery for insects.

Look closely

A ribbed rim surrounds the opening. The lid above it does not close over the prey.

Utricularia vulgaris . Thierry PERNOT · Photograph · CC BY-SA 2.0 fr .

[Photograph](https://commons.wikimedia.org/wiki/File:Utricularia_vulgaris_traps_(01).jpg)

[CC BY-SA 2.0 fr](https://creativecommons.org/licenses/by-sa/2.0/fr/deed.en)

Utricularia vulgaris

### A tiny bladder sucks water in.

The plant pumps water out of the trap. When the door gives way, the pressure difference drives water and prey inside.

Look closely

The little swellings on the submerged branches are traps. The flowers can rise above the water.

Genlisea violacea . Noah Elhardt · Photograph · CC BY-SA 3.0 .

[Photograph](https://commons.wikimedia.org/wiki/File:Genlisea_violacea_giant.jpg)

Genlisea violacea

### A maze lined with inward-pointing hairs.

Underground leaves branch into twisted tubes. Hairs inside make it harder for tiny organisms to turn back towards the exit.

Look closely

The white structures are leaves modified into traps, lifted out of the growing medium so they can be seen.

Underwater, everything changes

## You blinked. The prey was gone.

Researchers filmed Utricularia traps sucking water in within less than a millisecond. Opening and closing the door add time to the full sequence, which is still difficult to follow with the naked eye.

< 1 ms · suction, in the 2011 study

Water has been pumped out.

Slowed explanatory sequence; shape and movement are schematic. The submillisecond duration describes suction, not the entire sequence. The study included U. vulgaris, the photographed species. Vincent et al., 2011 ↗

Now recognise the trap

## Which plant would catch you?

Three situations. Choose the mechanism that explains each capture.

You land on a glistening leaf. Your legs get stuck. What caught you?

Sundew. The drops on its tentacles are a sticky secretion.

You swim past a tiny bladder. A door opens and water drives you inside.

Bladderwort. A pressure difference creates a current that carries prey into the trap.

You fall into a container of liquid. Its lid stays open.

Pitcher plant. The pitcher retains its prey; the lid does not work like a jaw.

## Carnivorous plants grow in Romania, too.

The round-leaved sundew, Drosera rotundifolia, is native to Romania too. The gallery photograph shows another species in the same genus, Drosera capensis.

## How we know

Trap research, botanical explanations and photographs that let you see for yourself.

Research and explanations

Kew Science · Plants of the World Online. Drosera rotundifolia . Romania is listed within its native range.

[Drosera rotundifolia](https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:319182-2)

Royal Botanic Gardens, Kew. Carnivorous plants explained . Why plants hunt and the forms their traps take.

[Carnivorous plants explained](https://www.kew.org/read-and-watch/carnivorous-plants)

Pavlovič et al. (2014). Feeding on prey increases photosynthetic efficiency in Drosera capensis . Prey-derived nutrients and photosynthesis.

[Feeding on prey increases photosynthetic efficiency in Drosera capensis](https://doi.org/10.1093/aob/mct254)

Burri et al. (2020). A single touch can provide sufficient mechanical stimulation to trigger Venus flytrap closure . Touch, electrical signals and exceptions to the two-touch rule.

[A single touch can provide sufficient mechanical stimulation to trigger Venus flytrap closure](https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000740)

Nakamura et al. (2013). Jasmonates trigger prey-induced formation of an outer stomach in carnivorous sundew plants . Movement of sundew tentacles and leaves.

[Jasmonates trigger prey-induced formation of an outer stomach in carnivorous sundew plants](https://doi.org/10.1098/rspb.2013.0228)

Bohn & Federle (2004). Insect aquaplaning: Nepenthes pitcher plants capture prey with the peristome . Why insects slip on a wet pitcher rim.

[Insect aquaplaning: Nepenthes pitcher plants capture prey with the peristome](https://doi.org/10.1073/pnas.0405885101)

Vincent et al. (2011). Ultra-fast underwater suction traps . Pressure, the trapdoor and suction duration in bladderworts.

[Ultra-fast underwater suction traps](https://doi.org/10.1098/rspb.2010.2292)

Martín-Roca et al. (2025). The carnivorous plant Genlisea harnesses active particle dynamics to prey on microfauna . The tubes and inward-pointing hairs.

[The carnivorous plant Genlisea harnesses active particle dynamics to prey on microfauna](https://doi.org/10.1073/pnas.2409510121)

The photographs

Image resized; some views show a partial crop.

Dionaea muscipula Noah Elhardt · Photograph · CC BY-SA 2.5 .

[Photograph](https://commons.wikimedia.org/wiki/File:Venus_Flytrap_showing_trigger_hairs.jpg)

[CC BY-SA 2.5](https://creativecommons.org/licenses/by-sa/2.5)

Drosera capensis Luc Viatour / Lucnix.be · Photograph · CC BY-SA 3.0 .

[Luc Viatour / Lucnix.be](https://lucnix.be/)

[Photograph](https://commons.wikimedia.org/wiki/File:Drosera_capensis_Luc_Viatour.jpg)

Nepenthes villosa kallerna · Photograph · CC BY-SA 4.0 .

[Photograph](https://commons.wikimedia.org/wiki/File:Nepenthes_villosa_Mt_Kinabalu_Sabah_Borneo.jpg)

[CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0)

Utricularia vulgaris Thierry PERNOT · Photograph · CC BY-SA 2.0 fr .

[Photograph](https://commons.wikimedia.org/wiki/File:Utricularia_vulgaris_traps_(01).jpg)

[CC BY-SA 2.0 fr](https://creativecommons.org/licenses/by-sa/2.0/fr/deed.en)

Genlisea violacea Noah Elhardt · Photograph · CC BY-SA 3.0 .

[Photograph](https://commons.wikimedia.org/wiki/File:Genlisea_violacea_giant.jpg)