May 16, 2017
Ants
They’re cool
Adil, 5–16–17
Ants are almost everywhere — literally. They’ve been around for 110–130 million years (thus far outlasting the dinosaurs), and they’ve colonized every landmass on Earth except Antarctica, the Arctic, and a select few islands. Some evidence suggests there are about 10,000,000,000,000,000 (10 quadrillion) individual ants alive on Earth at any given time, and they represent ~15–20% of the total terrestrial animal biomass, thus exceeding that of all the vertebrates! (Another estimate is that there are ~1.5 million ants on earth for every human being, so that would be even more.)
Let’s dive into more details about these crazy critters.
Ants are silly strong, capable of hauling at least 50 times their body weight on their mandibles. This would be the equivalent of me tossing around 8 grand pianos. One recent study from Ohio State suggests they can actually carry much more than this, up to potentially 5000 times their body weight…
Ants are also pretty fast. At ~3 inches/second, it’s roughly equivalent to a human running 34 mph.
Ants can hurt you. Paraponera clavata, aka the bullet ant, delivers the most painful bite: according to some victims, the it is equivalent to being shot, hence the namesake. This little joyride of crippling pain can continue unabated for up to 24 hours. While bullet ants’ bites are considered the most painful, Jack Jumper Ants’ stings can actually kill you (luckily we’ve created an anti-venom for it).
Ants ain’t got no ears, so they hear by detecting vibrations on the ground via special sensors on their feet and knees. This complements the use of their eyes and antennae. But they have another trick up their sleeve: some ant species are even able to use the Earth’s magnetic field for navigation.
Ant queens can live for up to 30 years, which is 100x longer than solitary insects of the same size. Worker ants clock out after about 1–3 years.
Ant colonies have their own distinctive smell, so intruders can be immediately recognized.
Soldier ants use their heads as plugs to keep entrances to the nest closed to outsiders. They literally place their head into the nests’ holes to prevent entry; when a home ant wants in, he touches the guard’s head to let it know it’s a homie, and the homie is let through. What’s up with this vigilance, though?
Ants wage war, using strategies oddly mirroring those seen in human warfare. When they win, they are brutal: they demand food from the losers, and…
They enslave other ants. Some species are even dependent on slave labor from other species, so they actively wage war on other colonies to steal their pupae and enslaves the new ants upon hatching.
One particularly guilty species is Polyergus breviceps, endemic to the United States. These things have legitimately lost the ability to forage for their own food, care for their own young, or clean their own nest, so naturally they choose to just enslaves other ants to take care of this stuff. And they’re really good at it. When attacking another nest, warrior ants release a formic acid that triggers panic amongst the inhabitants and crushes their defenses. Then they swoop in for the easy kidnapping of pupae. In desperate times, even the queen herself will join the attack, barreling in and releasing pheromones that actually reduces aggression of the defending ants, making the kidnapping even easier. After this, the attacking queen hunts down the defending queen and kills her. Now, the attacker becomes the new queen, served by her new colony. All is not lost for the slaves; they have been known to stage rebellions where they “rip apart” the larvae of the slave masters, thus preventing colony growth.
Ants can have massive communities called supercolonies. Supercolonies are giant ant hills that can stretch over thousands of miles. The longest one covers over 3,700 miles and is home to >1 billon ants.
Ants are dope teammates. They can make living bridges to cross vegetation and water:
Ants can clone themselves. Can’t explain it any better than this:
Parthenogenesis is a form of reproduction where there is no need for fertilization, making the resulting offspring a clone of the mother. A group of Amazonian ants was found to give birth to clones of themselves, creating a colony with no males around and somewhat echoing the legend of the fierce Amazons who do not tolerate male company.
Not to be outdone, the males of the small fire ant, whose queens also practice parthenogenesis in giving birth to new queens, makes sure that their genetic legacy spreads on by cloning themselves. This special trick of the male small fire ant involves eliminating the female genome in some of the fertilized eggs, making the ant a perfect clone of the father. This unique reproductive maneuverings of both the female and male small fire ant results in a nest, composing of ants of the same species, that has the genetic makeup of three completely different species; the queen clones, the male clones, and the sterile female workers with mixed genes.
Ants are probably the smartest insect, with 250,000 brain cells in their tiny heads.
Ants learn interactively from each other, in a rare non-human example of such activity. They use a technique called tandem-running where the teacher runs along the student to show it the ropes and make sure it doesn’t goof up. There are experienced food foragers, janitors, and egg- and baby-caretakers that teach their skills to younger generations to ensure efficiency in the colony. The teaching is also a two-way interaction — thought to be the only non-human animals to do this. And if an ant is really struggling, the teacher recognizes this and slows down its teaching. If the ant consistently fails at the job, it can get relegated to another job that doesn’t require such specialized skills.
Ants farm. The only other species known to use agriculture are bark beetles, termites, and humans. Humans have been around for about 5 million years, but ants have been farming for ~50–70 million years. Before a queen moves out of her birth nest, she sneaks into the garden and scoops up some fungal pellets that will serve as the seeds for her new colony/farm. They even use pesticides and herbicides. Here are some examples:
The fungal gardens that ants grow are also home to a virulent kind of fungus that kills the fungal crops. To prevent this fungal weed from spreading, the ants have a bacteria at their disposal that they carry around on their cuticles. This bacteria produces an antibiotic that specifically suppresses the growth of the fungal weed. In their nests, they use several substances that inhibit the spread of parasites or weeds. The wood ants, for example, add solidified conifer resins to their nests while building them, which hinders the growth of bacteria and fungi. The lemon ant, which prefers to nest in trees, produces a natural herbicide that kills all other plant life surrounding their nesting tree, including grown trees. They do this by injecting leaves with herbicide, and the plants will start to die within hours.
Ants practice five known systems of agriculture, but all ants share basic principles in fungal gardening. Seems like a communal activity, again with knowledge passed down generations.
Ants raise livestock. Livestock includes insects like aphids, mealybugs, and myrmecophilous caterpillars, which secrete a sweet liquid called honeydew which ants “milk.” Ants shepherd their flocks around different feeding areas, protect them from predators, and bring them along when they migrate. When it’s milking time, ants simply tap their livestock with their antennae.
They dispose of their dead. Humans and elephants are the other main examples of animals doing this. Typically, there is even an ant “undertaker” that is responsible for moving the body outside the colony, thus preventing infection or disease from spreading to other colony members.
Interactions with Humans
Ant eggs are eaten as delicacy in Mexico (called Escimoles; also eaten in other countries under different names), with prices ~$40/lb. Insect caviar, yum.
Ants are used for wound healing. The Masai tribe of East Africa has found an ingenious way of healing their minor wounds: find a colony of army ants, select some of the biggest ants, and let them bite the edges of your wound. Finally, rip off just the ants’ bodies, leaving the heads and their pincers attached. These serve as makeshift staples and can last for days, easily replaced if needed.
Sources:
https://www.thoughtco.com/fascinating-facts-about-ants-1968070
