Summary: Let’s talk ant anatomy! Join Kiersten as she discusses basic ant anatomy, as well as a few unbelievable anatomy specializations.

For my hearing impaired followers, a complete transcript of this podcast follows the show notes on Podbean

Show Notes:

“Ant Body Structure” - Harvard Forest: https://harvardforest.fas.harvard.edu

“Ant Anatomy” - Ask a Biologist, Arizona State University: https://askabiologost.asu.edu/explore/ant-anatomy

“Tales from the Ant World” by Edward O. Wilson

“Adventures Among Ants” by Mark W. Moffett

Music written and performed by Katherine Camp

Transcript

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Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

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Kiersten - Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

So far we have talked about some extraordinary ant behaviors and we have so much more to explore, but I thought we should look at an individual ant before we move forward. The fifth thing I like about ants is their anatomy.

Ants are classified as insects, so they have three body parts: head, thorax and abdomen. They have an exoskeleton made of chitin. Chitin is the second most abundant amino polysaccharide polymer found in nature. It is hard and protects the internal organs of insects and gives their body structure. 

The head of an ant typically hosts two compound eyes, two antennae, two mandibles and a mouth on the outside while internally it houses the brain. Many species also have ocelli in the middle of the head, as well. The compound eyes contain hundreds of lenses that combine to form a single image. Species that use vision to hunt for prey will have larger compound eyes, while those that rely on other senses will have smaller compound eyes. All species of known ants have antennae, typically two. The antennae will be constantly moving as the ant tastes, touches, and smells everything it comes in contact with. The antennae will bend in the middle like a human elbow allowing maximum flexibility. Mandibles are super important to ants and they will vary by species. Some of them are extremely specialized and we will go through a few of those species in a moment. In general, mandibles are used to grasp anything ants need to pick up or carry. They are also used to bite, crush, cut, dig, fight, and hunt. Just behind the mandibles is the mouth which is used to eat, clean themselves, and groom nestmates. The last item on the head is the ocelli. Ocelli are simple eyes that detect light. Ant head shape will vary greatly between species and that is dependent on what they eat and how they build nests.

The second segment is the mesosoma. Now, I just said ants have three segments and the second segment was the thorax, right? I did and this is technically correct, but the last two segments aren’t clearly visible. The mesosoma actually contains the thorax and the front of the abdomen. The mesosoma segment is full of muscles and is where the legs attach to the ant’s body. Ants have six legs. Their legs are made for movement and most ants can run fast when needed. Each leg has four segments and a hooked claw at the end of each leg helps the ant climb and hang onto surfaces.

The third segment is the abdomen which is made up of the petiole and the gaster. This is the segment that contains all the important internal organs that keep the ant alive, besides the brain which is located in the head. The heart, the digestive tract, and the chemical weaponry is all found in the gaster. The chemical defense system will vary by species. Ants can have a stinger with which to inject venom into prey or predator or they may have a small opening through which they can spray acid to stun prey or defend themselves.

In between the mesosoma and the gaster is the petiole. This structure attaches the mesosoma and the gaster together giving the ant enough flexibility to sting or spray acid in different directions. Some species of ants will have a second attachment segment called the post-petiole. 

Ant can have separate classes of workers, major and minor workers. They perform different activities. Minors typically take care of the young, clean and build the nest, and gather food. Majors are often soldiers, guarding and defending the colony. Some species will have size differences between these castes and can have modified anatomy to fit their specific jobs.

Queen anatomy is slightly different as they are the only ant in the colony making babies. The body will still have three segments, like an other ant as well as all other anatomical parts we have discussed thus far. They will have wings at birth so they can make the nuptial flight but they will lose them soon after reproduction and establishing her new colony.  

The queen is typically larger than the other worker ants in the colony. Her gaster will be large because it contains all of her important life-giving organs and her reproductive system. Her mesosoma is also large because she needs more muscles to power flight.

As I have stated before, all workers in a colony are female, so male ant anatomy is slightly different. They have wings like the queen so their mesosomas are large and muscular. They may be bigger than some workers but are often not as big as a queen. Their eyes are typically smaller and their antennae are straighter. Their reproductive organs will be large. They don’t live very long and are made for only one thing, mating.  

Now ant anatomy can be specialized for certain species and I thought we’d talk a little about some of these unique features.

Certain canopy ants that spend most of their lives in trees have an internal sac to store liquid called a crop. They can transport tree sap to their sisters in this sac and regurgitate it to feed to them when needed. Kinda like birds. There is also an oral pocket that most ants have in which they store detritus that they clean off each other or strain off a meal before consuming it. Once a day, ant workers will spit out a pellet in the midden pile that is full of this detritus, like an owl pellet! Weaver ants have a sternal gland specific to their family that releases a short-range pheromone during war or hunting to call her sisters to her aide.

One on the most diverse parts on an ant is the mandibles. Each species’ will shapes will be dictated by what they eat. Some are so specialized that they are modified to eat only one type of prey. 

One of the most abundant ants in the world, the dacetines, are small ants with long mandibles that snap together like spring traps. Why would such a small ant need such vicious, fast snapping mandibles? Because they eat springtails. Springtails are small invertebrates that jump fast and high, so these ants have developed mandibles that help them catch this specific prey. Thaumatomyrmex, or miracle ants, have mandibles that look like wicked pitchforks. Their mandibles consist of a flat base that ends in a row of long spikes. Yikes! Why do they need such scary looking mandibles? They eat polyxenid millipedes. These millipedes are covered with dense bristles that ward off most predators. The thaumatomyrmex mandibles allow them to impale the millipedes without worrying about the dense bristles. These ants also have an additional adaptation that allows them to eat these scary millipedes; pads on their forelegs that help them scrub the bristles off the millipede exposing the soft bodies. 

There are so many more amazing anatomical adaptations in the ant world, but I only have so much time. Thank you for joining me for the fifth episode of ants because my fifth favorite thing about ants is their anatomy.

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change. 

Join me next week for another exciting episode about ants.  

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This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, my very own piano playing hero.