Animals We Hardly Notice
Discussions about animal rights and welfare most often focus on mammals, birds and fish. These animals are relatively close to us, making it easier to recognise their fear, suffering or attachment. Much less frequently do we consider the fate of invertebrates, even though they account for around 70 per cent of all known animal species.
A mosquito drinks our blood, a fly lands on our food and a cockroach appears precisely where we would least like to encounter it. Our instinctive reaction is therefore to get rid of the unwelcome visitor as quickly as possible. But does the fact that an insect is troublesome or repulsive to us justify excluding it entirely from ethical consideration?
As Prof. Krzysztof Pabis points out, such an approach may be a manifestation of speciesism, the belief that human interests are inherently more important than the needs of other living beings. Yet even organisms that irritate us play an important role in nature. Mosquitoes, for example, serve as food for many bird species and contribute to plant pollination. Their disappearance could seriously disrupt ecosystem balance.
The World Through an Insect’s Eyes
To view insects differently, we should try to understand how they perceive their surroundings. Their world is not a poorer version of ours. It is simply different.
Insect eyes are composed of numerous tiny lenses known as ommatidia. They do not provide an image as sharp as human vision, but they may enable insects to observe almost their entire surroundings and detect movement exceptionally well. Some insects can also see ultraviolet radiation, allowing them to perceive patterns and distinctions that remain completely invisible to us.
Their other senses are equally impressive. A male moth can detect chemical compounds released by a female from a distance of several kilometres. A bed bug locates a human host by sensing body heat, exhaled carbon dioxide and dozens of chemical substances. Insects are also capable of tasting through receptors located on their legs.
Monarch butterflies migrate from Canada to small forested areas in Mexico, using the position of the Sun and the Earth's magnetic field. Bees, meanwhile, can learn to associate the colour of flowers with the quality of the nectar they contain. A small brain therefore does not mean an absence of complex behaviour.
Do Cockroaches Feel Pain?
This turns out to be the most difficult question of all. In cockroaches, scientists have identified nociceptors, receptors that respond to stimuli capable of causing harm to the body. These insects also possess brain regions that integrate sensory information, respond to pain-relieving substances, engage in behaviours that support recovery after injury and learn to avoid painful experiences.
This does not yet constitute definitive proof that a cockroach suffers in the same way as a human being or other vertebrates. Scientific debate on the matter is still ongoing. However, the available evidence is sufficient to challenge the convenient assumption that an insect is merely a simple “biological machine” devoid of sensations.
This issue extends far beyond a household encounter with a cockroach. Insects are bred for feed and food and are also widely used in laboratories. Electrodes are implanted in them, their responses to injuries are studied and researchers even attempt to control their movement. For many years, such experiments did not require the same level of ethical reflection as research involving vertebrates. Growing knowledge about insect abilities may, however, change the rules governing their breeding, control and use in scientific research.
Knowledge Before Judgement
We do not need to find a mosquito or a cockroach likeable in order to recognise the complexity of its existence. Science has not yet provided a definitive answer to the question of what it is like to be an insect. It does show, however, that creatures we readily regard as primitive and insignificant perceive the world in many sophisticated ways.
Perhaps, before the next automatic movement of a shoe, we should pause for a moment. Not because a cockroach should have the same rights as a human being, but because our lack of knowledge does not necessarily mean that another living being feels nothing.
The lecture “Czy mogę rozdeptać karalucha bez wyrzutów sumienia? Badania nad zmysłami owadów a nasze postawy etyczne” [Can I Step on a Cockroach Without Feeling Guilty? Research on Insect Senses and Our Ethical Attitudes], delivered by dr hab. Krzysztof Pabis, Associate Professor at the University of Lodz, was recorded during the Student Scientific Conference ”Jak powstaje w nas DOBRO?” [How Does GOOD Arise Within Us?]. The event was organised by the MÓZGOMANIACY Student Science Club and the University of Lodz Interfaculty Student Science Club of Science Communicators.
Edit: Michał Gruda (Centre for External Relations)
