After 7 to 14 days in their larval stages, ants begin to look more like ants than eggs. They begin to develop limbs, mandibles and segmented body parts. By the end of their pupal stage, fully grown ants emerge.
Ant pupae are larger than eggs and larva. Although it not true for all ant species, most of them have their pupa concealed in cocoons. Pupa cocoons are made of silk threads that are spun around the pupae as in a protective case. Inside there, the pupae develop and grow, working on their bodies in order to emerge complete and perfect at the end.
For ants that pupate naked, the pupa can be identified as the lightest often immobile ants. They vary between white and yellow in color. The different between ant pupae and adult ants is that the pupae have their feelers attached to the sides of their bodies and their general stature still resembles that of a fetus. The head is slightly bent with the abdomen slightly raised towards the bending head.
For cocooning ants, the pupae resemble a small white capsule with a distinct black spot at one end. The cocoons begin as white but by the time the pupae emerge, the cocoons seem darker. Inside the cocoon, the pupae seem to be in some sort of sabbatical or perhaps a boot camp where they constantly work on themselves in order to be ready and equipped for the next stage in life.
Some scientists went ahead to research on the reasons as to why some ants have cocoons while others do not yet at the end of the day, healthy fully grown ants emerge. Different reasons have been given for this slight difference during the metamorphosis of these social beings.
Some ant species, such as the wood ants seem to be very strict and serious about the state of hygiene of their nests. One of the major roles of worker ants is ensuring the hygiene of the nest is kept. They constantly clean and remove dirt especially around the queen and the young brood.
Ant larvae and pupae are the most vulnerable of the ant colony. This can be because of their lack of mobility. They cannot run or fly away when danger such as predators, floods or human intrusion comes their way. They rely fully on the adult ants to transport them to safety. This therefore means, that even in presence of disease, the pupae may not survive if they are not assisted.
The wood ants’ stand on cleanliness is so strict that when pupae are seen to be sick, they are thrown out of the nest without any second thoughts. Without anyone to feed, check or protect them, the pupae have little to no chance of survival outside the nest. They will either die of starvation or be eaten by predators.
To avoid this therefore, the pupa spin a water proof, bug proof and germ proof cocoon around themselves. By so doing, they are protecting themselves from contracting any fungal or bacterial disease. Bacteria and fungi have to get into contact with the skin of the pupa in order to infect them. However, with the presence of this external proof armor, chances of getting sick are significantly lessened and the pupae therefore raise their survival odds, at the same time preventing themselves from being thrown out of the nest.
During this stage, pupae seem to molt. This is shedding off of skin and it happens at least three times. The pupae also gather all the toxins, poisons and anything else unwanted in their systems and make them into one solid pellet. This pellet sticks out of the end of their cocoons and looks like a burnt spot on the surface of the cocoon.
In Weaver ants, the silk threads that the pupae use for spinning their cocoons, has other uses to the rest of the colony. The worker ants take this silk and use it to patch together pieces of collected leaf fragments that are used in the making of the nests.
In some cases, ant pupae make for food for the queen ant and sometimes some of the worker ants. This however happens only in extreme cases of drought and food scarcity. Usually the eggs are eaten first before the ants result to ingesting the pupae.
Ant pupae can make and understand sounds
Although it is not known by most people, ant pupae have been found to be able to make sounds and noises. After some research, scientists have recorded pupae making pulse like sounds. They are not continuous or joined as that of a song, or speech. They are more of singular, independent bursts of sounds. Similar to when water drips.
While researching as to why pupae and not larvae make these sounds, scientists found out that these sounds are meant to be a form of status claiming rituals. This is because only pupae that are higher up in the ant ranks are able to make and understand these sounds. Therefore, by crying out, they are in a way announcing their superiority.
In another scientific research, ant cocoons have been found to be buoyant. This means they have the ability to stay afloat in large water bodies. When army ants are observed after heavy rain, they will be seen forming large masses on the water surface and floating on to dry land. This can take some hours or some days, depending on the amount level of flooding.
What is interesting, is that, instead of the ants keeping the brood on top of the mass and taking them to safety, they are the ones shoved to the bottom of the floater. This may seem cruel because it is almost second to nature that animals save their young ones no matter what, because they ensure the continuity of life.
This is no different for the ants, as we have already seen that worker ants loyally defend their young against any external intrusion. It is more of a calculated move and an intelligent one at that. Ant pupae and larvae cannot move or run for their lives in times of danger. They cannot swim either. However, they are able to float, and so when there is a flood, keeping the brood at the bottom creates a form of raft for the rest of the ants.
The ants then get on board, keeping the queen at the center which is the most secure, and there float on to safer ground where they begin life afresh. If the worker ants had to swim and carry the brood at the same time, chances of survival would be very minimal. Another one of nature’s tricks perhaps.