Backyard Biology

Nature stories from my backyard and beyond

Nature Stories

Allegheny Mound Ants

Friday, May 7, 2010

Did you know that ants are one of the most dominant groups of animals around the globe. They are, in their own minute way, just as dominant as are humans. Consider this - though only a tiny fraction of the size of humans, the total weight of all the ants in the world equals that of all humans.
Ants are everywhere. Look closely at the bark of any tree. The first animal you are likely to see is an ant. Examine the grass in your back yard. Ants everywhere. Check out the sidewalk in front of your house or a rock wall in the woods. Ants, ants and more ants. In fact, just about everywhere you look, there is an ant.
Ants are social insects. They live in colonies. With so many ants around, it stands to reason that there must be ant colonies everywhere as well.

Find one!

Think to yourself, do I know where an ant colony is? Right now. At this moment.
Chances are most people would be hard pressed to find an ant colony. Oh sure, you might be able to go outside and look around and eventually locate one. However, most ant colonies don't attract much attention. Most people could not, with out leaving the comfort of their home, give directions to one ant colony.
Allegheny Mound Ant nest.
There are many mound building ants in our backyards. Think of the little cone of dirt that surrounds an ant hole. small mond ant nestYou are looking at a mound ant. Most mound ants build a cone about 1 inch high. The Allegheny Mound Ant mound can rise over 3 feet tall and stretch more than 6 feet wide! Once you have seen an ant nest this size, you are not likely to forget it! A great place to see these mounds is at the Willow Brook Farm nature preserve in Pembroke, MA.
To create a colony this size takes time - at least a few years. Therefore, they are usually located in undisturbed areas. As well as an undisturbed area, the ants prefer a sunny exposure to heat their nests. An ideal area is a field that is occasionally grazed but not mowed. An occasional grazing of the field will prevent the plants from growing tall enough to shade the nest.

Unlike honeybees, wasps and many types of ants, the Allegheny Mound Ant colony can contain many queens, all laying eggs in the same mound. One queen may leave with some of the workers to start a new mound. Does this make it a new mound or part of the old mound?
A large colony may consist of hundreds of thousands of ants. The tunnels they dig may extend three feet underground and over six feet past the edge of the mound. It is the dirt from these tunnels that creates the mound. The mounds may be completely bare of vegetation, or the vegetation may be growing around the base of the mound. Allegheny mound ant nest 2The top of the mound, however, is almost always bare. The sun shining on the mound helps to keep the chambers below warm, allowing the ants to grow faster. The ants are constantly moving the eggs and larva around in the colony to keep them at the right temperature. To take the most advantage of the afternoon sun, many of the mounds have a greater slope facing south, towards the afternoon sun. Some of the mounds in the Willow Brook Farm preserve are aligned this way and can be used as a rude compass.

Since sunlight is vital to keeping the nests warm, the ants will go to great lengths to keep the vegetation down. This includes eliminating small trees growing next to the colony. If a small tree is growing too near the nest, the ants will bite the bark with their strong jaws and squirt formic acid into the wounds they make. Eventually, this formic acid can kill the tree. If you are foolish enough to step on a nest, you will get the same treatment. They will run up your leg, bite you and give you a squirt of their acid. A dozen or more of these bites can be quite painful. I experienced it once as a child and it is an experience I will never forget!

Such a large colony of ants needs a large food supply to survive. Therefore, it is not surprising that these ants will eat just about everything and anything. They are scavengers, eating any dead insects they find. In this way, they help keep their countryside clean of insect roadkills.
They are hunters, overpowering and killing any live insect they find. They are not adverse to eating other ants. In fact, around a large Allegheny Mound Ant colony, there may be very few other types of ants. They also eat many pest insects. Studies have shown that populations of scale insects may be low around the nests. For this reason gardeners like these ants.
They are farmers. They will tend aphids, stroking them with their antenna until the aphid releases a sugary substance called honeydew. The ants lap up this honeydew and bring it back to the colony. In return, the ants protect the aphids from predators. Aphid populations may be higher in areas around the nests. For this reason gardeners don't like these ants.
If you sit by an ant nest and watch closely, you will see the ants bring all manner of food to feed their large family. If you sit by an ant nest and watch closely, chances are you will never forget where this most amazing ant lives.