Insect Undertakers

Insect Undertakers

The responsibility of managing the bodies of deceased insects does not sound like it would be a high priority for the colony, since countless insects die daily. But every type of eusocial insect actually has its own process for properly handling the dead insects for the good of the colony. Journalist and naturalist Ed Ricciuti explored the interesting implications of insects’ rituals in taking care of their dead, and has given explanations for each of the steps. This information has provided the general public with more information as to how these insects don’t get buried under their own dead species. If insects didn’t take care of their dead in the right way, it would mean a painful end to the group and their home.

Insects have Undertakers?!

In order to keep the colony going strong, each insect class has a set of specific jobs that helps the group at large. Some of the specific jobs include foraging for food, processing the gatherings, building and maintaining their home, and searching for a safer location. One less glamorous job is undertaking, or preparing the body and moving it to the proper place. The signal for the insect undertaker to begin their job is when the pungent chemicals are released from a recent dead insect. Since this is different than the normal state of homeostasis in the colony, the specialized insects know to solve the problem quickly before it begins to affect other members of the group. Bugs that live in colonies, like bees, ants, and termites, all know that if one dead bug stays inside the home long enough, it will infect the rest of the insects with whatever chemicals or infection killed it, thereby eradicating the whole colony. This is why the insects take measures into their own hands and dispose of the bodies quickly. 

Oelic Acid

When a bug dies, its body releases many different chemicals that notify its species of its presence. This tells the live insects to take care of the body before it infects the colony. The released chemicals include 3-octanol, 3-octanone (later on), and oleic acid. The oleic acid is a specific signal that the dead bug has been there for a while, and it is even referred to as the “death pheromone.” It slowly collects within the body after death, so the stronger it is, the longer the insect has been deceased. Oelic acid is found in dead insects from all classes, so any one that dies has a built-in signal that it died. It has been discovered that this fatty acid does build up more slowly in soldiers than in the rest of the colony, but it is still there for the undertakers to find. The bodies of worker insects give off the most 3-octanone and 3-octanol, especially right after death.

The response time to the scent put off by the oelic acid varies, but it has seemed to be quicker over time. Insects are constantly adapting and learning more about the manmade dangers the hard way, so they need some way to keep their species alive as best as they can. The instinctive reactions to the oelic acid are an evolutionary response that has grown over time to keep each generation of the colony alive. If not for this acid, bodies of insects may go unnoticed for quite some time, and slowly destroy the colony from the inside out. 

Management of Bodies

Each species of eusocial insect has its own process and rituals for disposing of their deceased brethren so as to keep the colony alive and their home clean. It all depends on the abilities of the insect, the type of home, and the location of the body. When the chemicals are put off by the body, it’s go time for the undertakers. The most common way of handling the situation, and the general first step, is to completely remove the body from their colony and nest. If the body isn’t in the home, it can’t infect the living insects with whatever substance or disease killed it. They will carry the dead insect out with whatever appendages are strongest, and begin the next steps of the job, which varies from insect to insect.

Ants: Ants are known for their incredible strength compared to their tiny size, as they can lift around 5,000 times their weight. Because of this, carrying their dead is not an outlandish task for them to complete. The undertaker will drag the body far away from the nest, and are quick to get the job done before anything worse can happen. Different species of ants have specific methods for ridding the nest of the body. Red ants in general tend to drag the bodies outside and put them in refuse piles, or kitchen middens. These are piles of waste, ant bodies, and trash that the ants keep outside of the nest in order to keep a tidy home. Think of it as taking out the trash, but in a more extreme manner. Other types of ants keep the bodies closer to the nest, but section them off from the main part. One such type is the leaf-cutter ant, which transports the bodies into tombs that are separated into chambers. 

Bees: Bees also like to keep a clean hive, so any dead bees need to be taken care of immediately. Honey bees in particular will first examine the body by feeling it with its antennae, then taking the body outside. The bee will use its mandibles to grab the dead bee’s appendages and drop it outside the hive, causing it to usually land on the ground and be ignored until it blows away or decomposes, unless a carnivorous insect gets to it first.

Termites: The termite is the most involved and advanced in its methods of dead insect handling. Every part of the process depends on the caste and the amount of time that the dead termite has been deceased. The order of how long each caste takes to be found when dead, from longest to shortest, is reproductive nymphs, soldiers, and workers. Nymphs put off far less pheromones, so they take longer to find. Soldiers take a long time likely due to their slow eminence of pheromones. Workers take the shortest amount of time to find because they have the most members and they are in the riskiest areas, which means that they have the highest risk of infecting the colony with strange diseases. And since thousands of termites die in a single colony every day, they have their burial methods down to a science no matter the caste and situation. 

The Methods of Termites

Termites definitely have the most involved methods for handling their dead out of any common insect, so it is worth looking into them specifically. The type of caste and number of bodies influence the method that is used, but they are all effective in keeping the colony alive.

Consumption: Yes, you read that right. Termites will eat their dead brethren up to sixty-four hours after they die. They do not always do this if there are a lot of bodies to bury, but it is a common practice for the undertakers when they have time. This is because there are still many nutrients within the body for that amount of time, and the surviving termites need all the energy they can get in order to continue working and gnawing wood. Specifically, the nitrogen content in the bodies is higher than wood, so the living termites can get this important resource before they go back to eating. 

Burial: Once the termite has exceeded the appropriate amount of time to be eaten, the typical next method is burying it. This method is also great for blocking off potentially harmful infections, like by a fungus. Since termites live in the wood they gnaw through, they do not have dirt to bury their dead under. So instead, they use a combination of chewed food, saliva, and feces to properly cover the bodies. This prevents the fungi and pesticides from infecting the rest of the colony. Workers are often immediately buried due to their proximity to riskier locations and work, since they are the ones foraging and doing the actual undertaking. And since they are by far the largest caste, it is easier to bury many dead workers than to take the time to eat or wall them off. Soldiers can be walled off or buried, depending on the amount of bodies and location. The sealing-off of the bodies is an interesting process, and one that does not happen with every caste of termite. 

Tombs: This is an interesting method that termites use in order to protect their home from any lingering diseases. Although walling off termites and sections of the nest takes time and effort, it is still easier and more reasonable to do than to completely move out and relocate everyone. The walling off is seen as a response to dangerous chemicals and pesticides that the termites can smell, so they may section off part of the nest without any dead termites in it simply because it is so pungent with deadly chemicals. Termites will use the same materials as the burial – feces, food, and saliva – to wall off sections of the nest that could potentially infect the colony. Worker termites are constantly working hard and repeating the same burial methods for their dead, but they do so for the good of the colony.

Termites are annoying and damaging pests that should be eradicated as soon as they are discovered in the home, but their processes for death are admittedly impressive. It is no wonder that they seem to arrive in endless hordes, since they work so hard to keep their colony healthy and strong. 

Pest Control

Pest control technicians know the specialized habits of these eusocial insects, and can properly get rid of them because of their knowledge. If the undertaking process is interrupted enough, it will be a quicker and easier way to dispose of the pests as a whole group. Contact our team to find out your options for the pest problems at hand. The pests may be living in harmony with their specialized jobs, but that does not mean they can stay in your home.

Citations

Ricciuti, E. (2021, February 17). Funeral or feast: How termites manage their dead. Entomology Today. Available at https://entomologytoday.org/2021/02/17/funeral-feast-how-termites-manage-dead/  (Accessed on March 10, 2022). 

Ricciuti, E. (2022). Flavipes Funeral: How termites manage their dead may have pest management implications. Pest Control Technology, 50 (2), pp. 34-42.