This is a question many gardeners often ask, especially when they are in the process of preparing their herbaceous perennials for flowering. My answer to this is an emphatic “no”. For one thing, carnivores have evolved over the eons into efficient hunters and certainly do not suffer pain at the point of attack as humans do. Plus, as a matter of fact, plants on which carnivorous plants thrive do not even feel pain under any circumstances. It would be ignorant to assume that some plants feel pain because they are not capable of speech.
Secondly, plants feel pain only if they are cut or damaged somehow. And the only way carnivorous plants can cause damage to other plants is by immobilizing them with their claws and eating the affected cells. Yes, some plants can secrete toxins that can cause disease in susceptible people, but these will not kill healthy tissue and organs. If a plant’s stem has been killed by frost, for example, it will grow out again in time (assuming it grows at all) as long as it is kept warm enough by morning dew or sun.
Thirdly, even though plants feel pain, they are not in the habit of hurting each other. It would be very dangerous for a carnivore to drag its prey across the lawn while cutting away at its flesh with its teeth! And, carnivorous plants often feed on each other. They often sip the juices of each other or even bite off one another’s flesh!
So, the question “do carnivorous plants feel pain?” is merely a red Herring. The best answer to the question is this: plants do have nerve endings (which receive signals from various parts of the plant to send signals to the nerves in the body) and some can sense other plants’ moves. They may move towards or away from each other, but if the other plant is harmful (say a vine that is causing too much damage) or the surrounding area inhospitable (a wet or damp area), the plant will “cough” or “snort” to signal its danger and will not move.
And, of course, there are some carnivorous plants which do not “feel pain” at all! Most familiar plants are carnivores because they have front-row access to sunlight which comes freely at their backs. Plants without back-rows cannot get direct sunlight. All carnivores move towards plants that come into their range, so plants with large, easily-reachable leaves are prime candidates for predation, and so plant hormones are activated and the feeding starts!
Plants have three major needs: food, protection and water. Plants require food to sustain themselves; they also need protection from harsh weather conditions. Some plants, such as grasses, may not appear to feed at all, but are actually “absorbing” plant food by means of stalks and underground runners. Leaves are covered with a thin film of saponin, a waxy substance that protects the plant against most predators. Water helps plant roots to grow and spread out. If a plant does not get enough water it will die.
Herbivores generally eat plant matter and leaves, but do not appear to feed on any living matter at all. Carnivores have sharp teeth for meat, although most herbivores may have only one set, and that is for eating plant leaves. Herbivores and carnivores differ in other ways, but the way they relate to plants is similar enough that we needn’t discuss those. Carnivores generally eat more, larger meals than herbivores, although a small number of herbivores eat some plant matter, just like carnivores.
The best explanation we can give for do carnivorous plants feel pain, is that they do have some sort of genetic memory, inherited from their ancestors. Certain types of plants have evolved over millions or even billions of years without change. In such cases, an ancestral animal is programmed to respond to its environment, and to use that experience to ensure its own survival. However, evolution can be random too, with plants evolving to meet the needs of their environments only over short spans of time. In that case, when an animal ancestor with a particular genetic trait suddenly becomes extinct, there’s no leftover programmed response to save that animal from extinction.