Giant African snails in Venezuela - Part 3: Snails suffer... Myth or reality?

The heavy and prolonged rainy season in Venezuela has favored the reproduction and appearance everywhere of snails; those small, slow, slimy and crawling creatures that many people find disgusting. Not surprisingly, unlike spiders and other common insects, snails by nature welcome a humid climate with open hands while fleeing from the strong sun that may well scorch their vulnerable bodies.

^{⬆️ Snails in my backyard. Can you help me recognize the species? (Own photos)}

But not all snails are this small. An African species called Lissachatina fulica justifies well its common name of giant land snail, because it is indeed gigantic, with some specimens that can fit the hand of an adult person. This snail has been proliferating in several parts of Venezuela, but unfortunately it is not welcome, since it is an invasive species and as such, harmful.

This is what we have been talking about in our first two articles on the subject, where we have answered questions such as What do we know about these animals, why the collective fear of them, is their extermination justified? and what methods are available to kill them? In this third installment we will address the last outstanding issues related to the conjecture of whether these animals experience suffering and whether this is an ethical problem or rather a misunderstanding of the urban myth type.

What's up with the suffering of snails?

Anyone who has ever accidentally tasted a mouthful of salt will know that the taste and sensation are quite unpleasant. Then imagine seeing yourself burned by the salt to the point that your body literally melts or dissolves. It's an unpleasant mental exercise, but it pursues a point: it's easy to imagine that it must feel like real torture.

^{⬆️ Melting to death must not be pretty. GIF: ZeTrystan}

Well, that's the melting reaction that land snails more or less experience when exposed to salt.

We've seen that the salt killing method is quite common due to its effectiveness, and is recommended by health and environmental authorities in Venezuela. Salt kills land snails and slugs by causing severe fluid loss or death by dehydration, something very vivid in the video above.

That's why some gardening commentators say that the method of killing snails using salt is a "cruel death" for them. This is how one a writer for the website slughelp.com puts it, adding that "This method shows little compassion and the slugs must experience significant suffering. I cannot understand this approach".

His concern is intuitive and shared by many people, because with the hypothetical situation I narrated above, we can conclude that for a human being to experience what happens to the snail must be unthinkable and clearly unacceptable. The same if we think of other types of animals such as mammals. We will know immediately that they are suffering by the display of their movements, cries and sounds that immediately communicate their pain to us.

Not so with snails, as they are slow and silent creatures. They don't have vocal cords nor can they produce sounds. However, their body can react to stimuli and in a somewhat graphic way, as we have already seen.

This is why animal rights activists and many people of conscience consider this inhumane. In fact, the gardener author of the above-mentioned article proposes several effective alternatives for killing snails and slugs "the humane way".

But do snails feel pain?

If we start from the premises 1) snails are animals, 2) pain is a sensation produced by a nervous system and 3) science studies these things carefully, then we can conclude that it is a question of scientific interest and it is science that can give us the answer.

Well, there has been some scientific research on this. The most notable one I have found is the one carried out by the Norwegian Scientific Committee for Food Safety called Sentience and Pain in Invertebrades, which studies the case of several animals such as worms, crustaceans, spiders, insects and mollusks (including snails and slugs).

^{⬆️ Different kinds of invertebrate animals. Can they all experience pain? Picture: Wikimedia Commons.}

In psychophysiology, a noxious stimulus is a change in the animal's tissues induced from the inside or outside that can cause damage to the animal. The nervous system of many animals has evolved to detect these stimuli by means of two capabilities: nocioception and sensitivity. Nocioception detects the raw stimulus and produces an automatic and unconscious response, while sensitivity is more complex and is the basis for stress and pain.

According to the study, snails are among the group of invertebrate animals that "most likely" have only nocioception but no sensitivity. In other words, when the snail receives a noxious stimulus, either by being touched, stepped on, having salt sprayed on it or something else that physically hurts it, then its organism will react to defend itself, either by retracting its antennae or body into its shell, or by secreting fluids, etc., which is a reflex response.

The same applies to other invertebrates such as cockroaches, locusts, worms and others, which are more communicative. We see that when they are stepped on, cooked, pierced or otherwise physically abused, they will react violently by shaking, jumping, squirming, etc., giving the impression that they are feeling pain, but in reality it is only a reflex response out of pure nocioception.

The scientific understanding is that snails and other invertebrates such as insects do not have the capacity for sensitivity, since their nervous system is very simple. This conclusion is reached mainly through the argument of analogy with the application of comparative anatomy, i.e., the nervous system of more complex animals such as mammals is compared with that of invertebrates such as snails and it is seen that the latter do not possess the features that allow the former to develop sensitivity and, therefore, to experience pain.

This being so, the best conclusion we can logically reach is that snails could not feel pain in the same way as other animals, especially humans, could. Hence, the belief of many people that these animals are experiencing a cruel and painful death by exposing them to salt, at the very least, it does not show fidelity, they are not feelings that can be matched, it is a bad comparison.

So why talk about the slaughtering of these animals in terms of humane and inhumane?

Because people want to show empathy. Homo sapiens is a rational animal as its own scientific name says (sapiens), but another quality also very outstanding of this species is empathy. We are able to imagine ourselves in the shoes of others, understand what others are going through and have a desire to show solidarity.

Some scholars in fact say that the capacity for empathy has been key to our survival and progress and is something in which we are better than any other animal. This gives rise to interesting philosophical elaborations such as those of Fernando Savater who says that "we are not born human beings, but with the capacity to be human beings".

Therefore, from the point of view of science, to speak of human methods of killing snails is unfounded. It is a projection we make on other living beings, especially if they exhibit behavior that disturbs us. For example, let's look at the following video:

Could we say that the ingested paramecia are experiencing a panic attack? In principle yes, but if we give it some thought, we will discover that the paramecia do not have a brain! They're single-celled organisms, they don't have a nervous system. However, their behavior is so dramatic that it seems to be in panic. Actually, it is a very basic property of the unicellular organism called irritability that indeed allows it to react to the environment and recognize stimuli that favor or compromise its survival, but from there to sensations of pain, fear and suffering there is a lot of difference.

However, if we drop the recrimination of using humanity as a standard by which to measure others, does concern for the suffering of animals make sense? Of course it does. It makes sense if we are talking about animals that we know can experience complex sensations and emotions such as pain and suffering, of which there are many. Snails, however, cannot experience this as the best of our understanding to date reveals.

Of course, this does not convince all animal rights activists, who chide scientists that the science could be wrong and that we humans are not an authority to say that other animals are not suffering. Not all animal rights activists respect scientific knowledge, show confirmation bias, or perhaps have other motivations of a religious or philosophical nature or are driven by some kind of urban myths.

In summary

There is a place for all animals on this planet, driven by purely natural forces. When giant African snails arrive in Venezuela, they become an invasive species, as they negatively impact the ecosystem. Furthermore, when their arrival is artificial, i.e., human-caused, then the recognition of the problem becomes more evident.

Therefore, it is necessary to eradicate the species Lissachatina fulica from Venezuela. Killing these snails should produce less remorse because these animals do not experience pain and suffering as we do. Science tells us that their nervous system is very primitive, so they probably don't have the capacity of sensitivity, but only nocioception, that is, an involuntary reaction of the muscles to bodily harm, devoid of consciousness and pain in spite of appearances.

To ignore this and to affirm the contrary without such a solid basis as the scientific one is to incur in superstitions. Of course, this is not to say that snails and other invertebrates should be killed indiscriminately and made into a spectacle. In any case, this entails an ethical debate beyond what we have covered in these lines and some would say that humans are an even more dangerous species. Perhaps we will talk about this on a future occasion.

Notes

• Most of the sources used for this article have been referenced between the lines.
• The cover image was created from free or permissively licensed images from Wikimedia Commons.
• Unless otherwise noted, the images in this article are in the public domain or are mine.