By Simon Knutsson

First written: Sep. 2015; last update: Oct. 27, 2016

Summary

If I died and was offered to be born again as an insect or cease to exist, I would definitely choose not to exist. This essay focuses on the quality of life of honey bees because they are well-studied, and on what have been suggested to be the most numerous insects: springtails, ants, termites, and aquatic insects such as mayflies and midges (although some sources no longer classify springtails as insects). There is enormous inequality among the fates of insects. Some die very young, either as larvae, pupae, or just after having emerged from the pupa stage as adults, and it is difficult to see how most such lives can be good on balance. Death often seems very painful so, because their lives are so short, they do not include enough positive wellbeing to compensate their suffering. On the other hand, successful honey bee queens can live for years while being fed, protected, and taken care of by others. In general, though, honey bees live short lives. The vast majority of them are workers who live on average only about 15–38 days as adults during summer. Mayflies and some midges have even shorter adult lives—they never eat, and they die within a few days. Ants and other kinds of insects live longer. This is probably fortunate from a population perspective, since it means fewer deaths per unit of time, although it may not be better for any individual to live longer.

Is it better to live longer?

It is probably better for the world if insects live longer, considering a group of insects, because it means that there are fewer deaths per unit of time in a given group. That is good since the process of dying may be the worst part of an insect’s life. But it is not clear that it is better for an individual insect to live longer. Living longer means more opportunity to have positive parts of life that can be thought to make up for the bad parts, but it also means more opportunity to have more bad parts. For example, that an ant worker is expected to live longer than a honey bee worker may not be a reason to think that it is “preferable” or “better” to be an ant. But it is still interesting to understand life expectancies in part because if an insect dies very soon after coming into existence, it is difficult to see how such a life can be net good. In other words, data on life expectancies is interesting partly because the process of dying, e.g. being eaten alive, is presumably a really bad experience. If one lived for 100 years, it’s easier to argue that life could still be worth living because there’s so much room for other experiences. At the other extreme, if one only lives for 5 seconds and then gets eaten alive, it’s less convincing to claim that those 5 seconds made up for the experience of being eaten.

Honey bees

Honey bees are social and live in colonies where there are three castes: workers, drones, and the queen. The queen lays the eggs, drones are males whose job is to fertilize the queen, and the workers are sterile females who do not mate. The bees develop through the stages egg, larva, pupa, and adult. Many might guess that a successful queen has one of the best lives of any bee. She mates when young, can live for years, mainly lays eggs, and is taken care of and fed by workers. On the other hand, some honey bees die during the larva or pupa stages, or just after having emerged as adults. For such individuals the only positive part of life that I can see would be the eating during the larva stage. A worker or drone stays in an individual, small, hexagon-shaped cell in the hive through the egg, larva, and pupa stages, where the larva is fed by workers. The cell barely fits the full-grown larva or pupa, so it is difficult to imagine what besides eating could be good for the bee’s quality of life during these development stages before it becomes an adult and leaves the cell. Next, I will look closer at the lives of workers, drones, and queens separately.

Workers

The vast majority of honey bees are workers who live on average 15–38 days as adults during summer and longer during winter. Most worker adults survive until they are at least 2–3 weeks old; one study found that only 4–11% of them die during the first 10 days as adults. Although one can think of this as a surprisingly low “child mortality rate,” one should remember that they still have a very short life expectancy. For the first couple of weeks, adult workers mainly stay inside the hive and perform a range of duties, and then they start flying outside to gather supplies for the hive.

After they emerge as adults they go through an age-correlated progression of behavioral changes that has been called behavioral development. The youngest bees typically clean the nest and feed glandular secretions to larvae. Middle-aged bees perform nest construction, process food, and guard the entrance, while older bees forage outside the nest for food, water, and nest construction materials.

Each foraging worker “typically goes on ten food gathering journeys per day, each lasting approximately one hour.” It has been suggested that workers die from a number of causes including wear-and-tear, predation, and disease, but it is difficult to know how many die from each cause. For example, this video shows giant hornets attacking a bee hive. According to the video, “30 giant hornets can annihilate a colony of 30,000 bees in three hours.”

Drones

An adult drone’s life is different from a worker’s. Its only job is to be ready to fertilize a queen, and it is famous for being lazy since it does no other work. Drones eat a lot, either they are fed or they grab food from the hive’s storage. The mating takes place in the air outside of the hive. Adult drones live about 20–40 days. If a drone mates, he immediately dies since the reproductive parts break off during copulation. Drones can also be killed by their worker siblings.

If there is a fertile female in residence, the workers may withhold food from the drones or gnaw off the drones’ wings and legs.

During the winter season, the drones are of little use and they eat a lot of the food storage so there is a phenomenon that drones are killed in autumn by workers.

When nectar in the field becomes scarce, the workers drag the drones out of the hive and do not let them return, causing them to starve to death. Eliminating drones reduces the consumption of winter honey stores.

Queens

The queen lays eggs and does not, for example, gather food or defend against intruders. Queens that have just emerged from pupa to adult first try to kill rival queens in the hive.

Immediately after she emerges, the queen tours the hive to see if there is any rival queen hiding somewhere. If she finds one, the two queens will fight until one is killed. If the colony is not preparing to swarm, then the newly emerged queen seeks out potential queens hiding in comb cells. The queen pipes to make a special noise and the hidden capped queen responds. Immediately, the emerged queen locates the cell, tears it to pieces and kills the unemerged queen.

A queen’s sting “is only used to fight rival queens.” Because of this killing among queens, combined with the fact that bees can breed several queens at the same time, and with the fact that there is generally only one queen tolerated in a hive, it seems likely that most queens are killed before reproducing, perhaps even before emerging as adults.

A queen that survives makes an orientation flight after a few days and then brief mating flights. After successfully mating, she saves the semen for the rest of her life and lays some thousand eggs per day for about two to three years if she is long-lived. The queen is fed and taken care of by worker bees.

Honey bees compared to other insects

Compared to many other insects, I would guess that honey bees have lower death rates during the development stages (egg, larva, and pupa) and early adulthood. I would also guess that honey bees to a larger extent avoid uncomfortable and harmful weather conditions. They are protected by the hive, and the adults take care of the eggs, larvae, and pupae. Eggs are placed by the queen in cells inside the hive where they develop until adult bees emerge from the cells. And the young workers mainly stay inside the protective hive and only later start to fly out to gather food and water, which is when the risk of death rises substantially. The hive is not only a physical barrier against predators; workers also ventilate it, regulate the temperature, guard the entrances, and gather food for the developing bees and the young adults. This protected upbringing contrasts with the lack of support in species in which parents lay many eggs and leave them to fend for themselves.

The most numerous insects

According to C. B. Williams in 1964,

it is among the small species, such as Collembola, and among the aquatic insects such as may-flies and midges, or among ants and termites, that the large populations [of insects] will be found.

Collembola (springtails)

Collembola, also known as springtails, are no longer classified as insects, but when they were, they were considered the most numerous insect. Zoologist Peter Shaw says that “anywhere you go on a land surface I would put money that there are springtails just under your feet.” Whether they are classified as insects is morally irrelevant and we can think of them as insect-like animals. They are tiny and appear less likely to be sentient than bees, wasps, ants, and some other insect-like animals such as hunting spiders. The length of a springtail’s life seems to vary among different species.

Very few adults survive for more than 1-2 years (Hopkins 1997). However, life history differs with each species, some having a life cycle of 23 – 27 days, other of 5 – 10 months (Ashraf 1969). Species that occur in caves and extremely cold climates might live longer. Hypogastrura tullbergi, an arctic Collembola, does not even reproduce until the third year (Birkemoe & Leinaas 1999).

Ants and termites

Sources differ on whether ants or termites are the most numerous out of all insects in terms of the numbers of individuals alive at any given time. In addition, ants and termites, together with social bees and wasps, make up the majority of insect biomass, although not necessarily the majority of insect individuals.

All ants and termites are social and live in colonies, so they may get similar protection from their colonies as honey bees seem to get. There is some data supporting that social insects, particularly ants, live longer than solitary insects.

Compared with solitary insects, the life span of hymenopteran [wasps, bees, ants, etc.] workers is prolonged. For example, the mean life span for solitary insects is 0.1±0.2 years, while ant, bee and wasp workers reach a mean of 0.9±1.1 years. The life span of wasp and bee workers differ slightly from those of solitary insects but ant workers have much longer life spans. In the case of ants, the protected subterranean niche might also affect the evolution of life span.

But note that this quote is about ‘life span,’ which is an unclear term. In the words of professor and entomologist James R. Carey,

Whereas the standard life table functions such as life expectancy, cohort survival, and age-specific mortality are clearly defined and readily measured, life span is typically characterized in vague, theoretical terms such as “…the limit beyond which, even under the most favorable conditions, the members of a given species cannot survive.”

From an ethical perspective, it is uninteresting how long an animal can live; the interesting question is how long it does live, which matters because it affects what its life contains. Still, the quote suggests that ants live longer than many insects.

Midges and mayflies

“Midges are the most common and diverse aquatic insects in the world… Their numbers can range into the tens of thousands per square meter.” Mayflies and some midges live very short lives as adults; the adults never eat, and they die within a few days. And “the entire life cycle of the aquatic midge is usually completed in 2 weeks.” In contrast, the stages before adulthood (mainly the nymph stage) are much longer for mayflies, lasting a few months to up to two years. So it seems for mayflies that how one assesses the quality of life during the nymph stage could have a large effect on how much good and bad their lives contain.

Remember the unfortunate individuals

When thinking about the quality of life of wild animals, many seem to think of a ‘typical’ or ‘median’ animal of the kind in question. But it is also important to remember the individuals who have the worst lives. Analogously, if one looks at the typical Norwegian human, one may conclude that Norwegians are fine, but of course there are many individuals in Norway who suffer due to being victims of crimes, diseases, and so on. By just thinking about the typical individual, one overlooks the worse off individuals.

Appendix: Notes on method

It can seem hopelessly anthropomorphic to try to understand how good or bad the life of an insect is, assuming that it is sentient. I’ve avoided speculations about whether a bee might feel lonely, exhausted, or afraid. Instead, I’ve focused on what, from an evolutionary perspective, would be the most obvious sources of positive or negative experiences such as eating, mating, starving, being too hot or cold, and being subjected to severe bodily injury.

Works cited