By Simon Knutsson
First written: Sep. 2015; last update: Oct. 27, 2016
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.
- 1 Summary
- 2 Is it better to live longer?
- 3 Honey bees
- 4 Honey bees compared to other insects
- 5 The most numerous insects
- 6 Remember the unfortunate individuals
- 7 Appendix: Notes on method
- 8 Works cited
- 9 Footnotes
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 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.1 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.
The vast majority of honey bees are workers who live on average 15–38 days as adults during summer and longer during winter.2 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.3 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.4
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.5
Each foraging worker “typically goes on ten food gathering journeys per day, each lasting approximately one hour.”6 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.”7
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.8 Drones eat a lot, either they are fed or they grab food from the hive’s storage.9 The mating takes place in the air outside of the hive. Adult drones live about 20–40 days.10 If a drone mates, he immediately dies since the reproductive parts break off during copulation.11 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.12
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.13
The queen lays eggs and does not, for example, gather food or defend against intruders.14 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.15
A queen’s sting “is only used to fight rival queens.”16 Because of this killing among queens, combined with the fact that bees can breed several queens at the same time,17 and with the fact that there is generally only one queen tolerated in a hive,18 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.19 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.20 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.21
Collembola, also known as springtails, are no longer classified as insects, but when they were, they were considered the most numerous insect.22 Zoologist Peter Shaw says that “anywhere you go on a land surface I would put money that there are springtails just under your feet.”23 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).24
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.25 In addition, ants and termites, together with social bees and wasps, make up the majority of insect biomass,26 although not necessarily the majority of insect individuals.
All ants and termites are social and live in colonies,27 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.28
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.”29
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.”30 Mayflies and some midges live very short lives as adults; the adults never eat, and they die within a few days.31 And “the entire life cycle of the aquatic midge is usually completed in 2 weeks.”32 In contrast, the stages before adulthood (mainly the nymph stage) are much longer for mayflies, lasting a few months to up to two years.33 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.34
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.
- “Aquatic Midges (Blind Mosquitoes).” https://www.lakecountyfl.gov/pdfs/Public_Works/mosquito_and_aquatic_plants/aquatic_midges.pdf.
- British Beekeepers Association, “Life in the Hive.” http://www.bbka.org.uk/learn/general_information/life_in_the_hive.
- Caldwell, Dave. “For Honey Bee Queens, Multiple Mating Makes a Difference.” http://www.cals.ncsu.edu/agcomm/magazine/winter08/n_mating.html.
- Carey, James R. “Insect Biodemography.” Annual Review of Entomology 46 (2001): 79–110.
- ———. “Longevity Minimalists: Life Table Studies of Two Species of Northern Michigan Adult Mayflies.” Experimental Gerontology 37 (2002): 567–70.
- Chuck [pseudonym?] “Class Collembola.” https://www.dlia.org/class-collembola.
- Cutter, Ralph, and Lisa Cutter. “Bugs of the Underworld.” http://midcurrent.com/videos/the-life-cycle-of-midges/.
- Czekanski-Moir, Jesse, and the AntAsk Team, “Do Ants Really Have the Largest Biomass of All Species on Earth?” http://www.antweb.org/antblog/2010/10/do-ants-really-have-the-largest-biomass-of-all-species-on-earth-laurie-usa.html.
- FAO. “Chapter 2 Colony Life and Social Organization.” http://www.fao.org/docrep/t0104e/T0104E05.htm.
- Fleming, Nic. “Which Life Form Dominates Earth?” BBC. http://www.bbc.com/earth/story/20150211-whats-the-most-dominant-life-form.
- Fukuda, Hiromi, and Takeshi Ohtani. “Survival and Life Span of Drone Honeybees.” Researches on Population Ecology 19 (1977): 51–68.
- Hamdan, Khalil. “The Life Cycle of a Bee.” https://www.clemson.edu/extension/county/oconee/programs/beekeeping/Honey_Bee_Life_Cycle_in_Pictures.pdf.
- Hopkin, Stephen P. Biology of the Springtails: Insecta: Collembola. Oxford University Press, 1997.
- Hölldobler, Bert, and Edward O. Wilson. The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies. New York: W.W. Norton, 2009.
- Kramer, Boris H., and Ralf Schaible. “Life Span Evolution in Eusocial Workers–A Theoretical Approach to Understanding the Effects of Extrinsic Mortality in a Hierarchical System.” PloS ONE 8 (2013): e61813.
- MAAREC, “Seasonal Cycles of Activities in Colonies.” https://agdev.anr.udel.edu/maarec/honey-bee-biology/seasonal-cycles-of-activities-in-colonies/.
- “Mayflies.” http://people.westminstercollege.edu/faculty/tharrison/CityCreek/Aquatic_Invertebrates/Mayflies.html. A part of “Birds, Bugs and Bushes,” a Class Project by students in General Ecology (Biology 340) at Westminster College. Created Fall Semester 2001 under the direction of Dr. Ty Harrison. http://people.westminstercollege.edu/faculty/tharrison/CityCreek/Index.html.
- Meyer, John R. “Social Insects.” North Carolina State University, General Entomology ENT 425. http://www.cals.ncsu.edu/course/ent425/tutorial/Social/index.html
- Page, Robert E., and Christine Y-S. Peng. “Aging and Development in Social Insects with Emphasis on the Honey Bee, Apis mellifera L.” Experimental Gerontology 36 (2001): 695–711.
- Pallardy, Richard. “Abundant Animals.” Encyclopedia Britannica. https://www.britannica.com/list/the-most-numerous-organisms-in-the-world
- Sakagami, Shôichi F., and Hiromi Fukuda. “Life Tables for Worker Honeybees.” Researches on Population Ecology 10 (1968): 127–39.
- Stone, David. “An Introduction to Bee Biology.” http://www.beespace.illinois.edu/files/stone-bee-biology.pdf
- Williams, C. B. Patterns in the Balance of Nature: And Related Problems in Quantitative Ecology. London/New York: Academic Press, 1964.
- Winston, Mark L. The Biology of the Honey Bee. Harvard University Press, 1991.
- Zimmerman, P. R., J. P. Greenberg, S. O. Wandiga, and P. J. Crutzen. “Termites: A Potentially Large Source of Atmospheric Methane, Carbon Dioxide, and Molecular Hydrogen.” Science 218 (1982): 563–65.
- It takes about 20 days for an egg to develop into an adult (workers: 21 days, drones: 24 days, queens: 16 days). Page and Peng, “Aging and Development in Social Insects.” Individuals die during all stages but two studies found that about 60–80% of eggs develop into adults. Sakagami and Fukuda, “Life Tables for Worker Honeybees,” Tables 1–3; Fukuda and Ohtani, “Survival and Life Span of Drone Honeybees,” Table 2. (back)
- Page and Peng, “Aging and Development in Social Insects,” 704. The figure 15–38 days refers to the age starting from when the bee emerges as an adult from the pupa stage. (back)
- Sakagami and Fukuda, “Life Tables for Worker Honeybees,” Tables 4–6; Page and Peng, “Aging and Development in Social Insects,” 704. (back)
- “The newly hatched bee remains in the hive apart from orientation flights for about 21 days performing various duties… When it is 22 days old, the bee becomes a forager (field bee) and will leave the hive to visit flowers.” Hamdan, “The Life Cycle of a Bee,” 4. (back)
- Page and Peng, “Aging and Development in Social Insects,” 704. (back)
- Stone, “An Introduction to Bee Biology,” 8. (back)
- At 1:10 into the video. (back)
- Winston, The Biology of the Honey Bee, 41. FAO, “Chapter 2 Colony Life and Social Organization,” section “The Drone.” (back)
- FAO, “Chapter 2 Colony Life and Social Organization,” section “The Drone.” (back)
- Page and Peng, “Aging and Development in Social Insects,” 702. (back)
- Winston, The Biology of the Honey Bee, 41. (back)
- Stone, “An Introduction to Bee Biology.” (back)
- MAAREC, “Seasonal Cycles of Activities in Colonies.” Also, “In the early autumn they [the drones] are evicted by the workers and die.” British Beekeepers Association, “Life in the Hive.” (back)
- FAO, “Chapter 2 Colony life and social organization,” section “The Queen.” (back)
- Ibid. (back)
- Ibid. (back)
- “1. Bees construct up to 20 wax queen cells, which are acorn like and point downwards. 2. The queen lays fertilised eggs in each queen cell.” British Beekeepers Association, “Life in the Hive.” (back)
- “It is not understood (by man) why bees will only tolerate one queen but any attempt to introduce a second queen results in her death.” Ibid. (back)
- Caldwell, “For Honey Bee Queens, Multiple Mating Makes a Difference.” (back)
- “Relatively few [worker] bees die inside the nest, most just fail to return from foraging trips.” Page and Peng, “Aging and Development in Social Insects,” 704. (back)
- Williams, Patterns in the Balance of Nature, 104. (back)
- Hopkin, Biology of the Springtails, front flap. “The springtails, or Collembola, used to hold the title [as the most numerous insect], but they are no longer officially insects, but rather part of a larger subphylum that includes insects and several related creatures.” Pallardy, “Abundant Animals.” (back)
- “If world domination is a numbers game, few can compare with tiny six-legged, shrimp-like springtails, or Collembola. Ranging from 0.25-10mm in length, there are typically around 10,000 per square metre of soil, rising to as many as 200,000 per square metre in some places. The 6,000 known species of these wingless arthropods can be found in all manner of habitats all over the world, from beaches and cliffs to the Antarctic and the highest mountain ranges on Earth. ‘On tarmac you might need to go down a few inches, but anywhere you go on a land surface I would put money that there are springtails just under your feet,’ says Dr Peter Shaw, a zoologist at the University of Roehampton, UK, and the UK Recorder for Collembola.” Fleming, “Which Life Form Dominates Earth?” (back)
- Chuck, “Class Collembola.” (back)
- “It’s pretty safe to say ants are the most numerous insects in the world.” Fleming, “Which Life Form Dominates Earth?” “It hardly comes as a surprise that ants are the most numerous insect in the world. These colonial hymenopterans may number from 10-100,000 trillion individuals globally.” Pallardy, “Abundant Animals.” But Czekanski-Moir and the AntAsk Team, “Do Ants Really Have the Largest Biomass of All Species on Earth?” says that “the world-wide population of termites has been estimated at about 27 times higher than the ant population in a paper by Zimmerman et al. 1982.” The cited paper, Zimmerman et al., “Termites: A Potentially Large Source of Atmospheric Methane, Carbon Dioxide, and Molecular Hydrogen,” says “the world’s termite population (2.4 × 1017)” on page 564. (back)
- The front flap of Hölldobler and Wilson, The Superorganism, says that “social insects—ants, bees, wasps, and termites—make up as much as two-thirds of insect biomass.” And on page 5 it says that “social insects—the colonial bees, wasps, ants, and termites—are species for species the most abundant of land-dwelling arthropods. Although they represent only 2 percent of the approximately 900,000 known insect species in the world, they likely compose more than half the biomass.” (back)
- Meyer, “Social Insects.” (back)
- Kramer and Schaible, “Life Span Evolution in Eusocial Workers,” 1. (back)
- Carey, “Insect Biodemography,” 92–93. (back)
- Cutter and Cutter, “Bugs of the Underworld.” From the section called “The Life Cycle of Midges” at http://midcurrent.com/videos/the-life-cycle-of-midges/. (back)
- “The emerging [aquatic midge] adults usually swarm at night to mate. They do not feed and, consequently, only live for about 3 to 5 days.” “Aquatic Midges (Blind Mosquitoes),” 1. “The adult [mayfly] cannot eat because it does not have functional mouth parts or a digestive system.” Quote from “Mayflies,” a student project at Westminster College. See also Carey, “Longevity Minimalists,” 567. (back)
- “Aquatic Midges (Blind Mosquitoes),” 1. This source continues, “however, it is not uncommon for the life cycle to take longer.” (back)
- “Mayflies,” a student project at Westminster College. (back)
- I am very grateful to Brian Tomasik, Lukas Gloor, Jeffrey Lockwood, and Oscar Horta for comments on earlier versions of this text. (back)