Nature & Environment

Why have carnivorous plants never grown big enough to eat humans ?

By T.K. Randall
June 7, 2025 ·  4 comments

Imagine a world in which plants are big enough to eat people... Image Credit: Dall-E 3 Anyone who has watched Little Shop Of Horrors will be familiar with the concept of a plant that's large enough to gobble up human victims, but in the real world, even the largest carnivorous plants are only capable of trapping and consuming small animals such as lizards and frogs.

There are many mechanisms used by these plants to trap their prey, ranging from the sticky leaves of the Cape sundew plant to the famous trap-like leaves of the Venus flytrap.

So why is it that plants large enough to trap and consume human-sized animals have never emerged, even though carnivorous plants have existed for millions of years ?

One reason is that neither the energy nor structural requirements necessary to trap something that large are actually possible with plant physiology.Furthermore, many carnivorous plants catch live prey to help compensate for the fact that they tend to live in swamps and other places with nutrient-poor soil.

Scaling up to catch humans would require far more nutrients than they would ever have access to.

On top of this, there is no real evolutionary pressure on these plants to grow to enormous sizes - catching small animals and insects is sufficient for their needs and the resources required to grow larger would outweigh the benefits that such a size would offer.

In other words, we won't be seeing people being eaten by giant carnivorous plants anytime soon.

Source: Smithsonian Magazine | Comments (4)

Tags: Plants