Sunday, February 18, 2024

Black Carpenter Ant

Few other insects are considered as annoying or unwelcome as the lowly ant. One in particular wreaks havoc on many homeowners. The black carpenter ant has established itself as an interloper within human dwellings. These large black ants are easily identified by size alone. Workers reach ¾ of an inch in length and queens as much as an inch! They are uniformly black with whitish hairs covering their thorax and abdomen. It is difficult not to worry when we see one of these large ants roaming our home. We may ask ourselves if we have an infestation or if this sighting is a single individual that somehow made its way into our living space.  

After all, we know these ants are fond of wood, and with most homes being made of wood, how long before the ants cause structural damage? A common myth associated with carpenter ants is that they consume the wood they chew. In fact, they are not eating the wood at all, they cannot digest the cellulose the wood contains. Instead, they use the wood to excavate their homes. These ants are capable of excavating large galleries consisting of a tunnel system they use to travel through their nests. Many of these tunnels lead to food sources, often in the form of an aphid colony that they farm for the secretions aphids produce called honeydew. These galleries are most often created in forested areas inside hollowed trees, decaying logs, under stones, or other debris. This chewing and tunneling activity performs a valuable

service within the woodlands by speeding up the decomposition of decaying wood. However, not so much in our homes. Because these ants are attracted to moist wood certain areas of our homes may be prone to an infestation. Roof eaves, around and under windows, decks, and porches are all susceptible to moisture and thus open to a multitude of carpenter ants chewing and excavating their way through your structure.

Black carpenter ant colonies may contain up to twenty thousand individuals, made up of a single queen, major and minor workers, larvae, males (drones), and eggs. The primary nest will house the queen, eggs, and many major and minor workers. Satellite nests are created nearby that contain the older larvae, pupae, some winged individuals (future queens), and the males. 

The satellite nests do not need to contain the proper moisture levels as the primary nest does for proper egg production and health. After about four or five years the colony is considered mature and the queen will produce eggs that are destined to be winged females and males, these are the reproductive individuals that will leave the colony, mate, and start new colonies, thus spreading their population to new locations. The winged members of the colony typically spend the winter within the nest. When spring rains and warmth return the winged individuals leave the colony, often in huge swarms. Many times, I have witnessed large gatherings of winged ants, called alates, emerging from the ground. I often receive phone calls about this phenomenon. Many people want to know what is going on, why do the ants have wings? These winged ants will take flight and mate on the wing. Soon after mating the males die, and the females wander off in search of suitable areas to set up a new nest. Once a location has been found she will chew her wings off and begin setting up home, by laying eggs. She will care for her first daughters herself until they are fully developed workers. With approximately twenty new workers, the queens' sole job is to lay eggs and grow the colony, whereas the workers are now responsible for retrieving food and feeding the queen and their developing sisters. Nests that have tunnels leading to aphid colonies have developed mutualistic benefits with each other. The minor workers will stroke the antennae of the aphids causing them to release the sugary honeydew the ants favor and need as an important energy source. The aphid gains bodyguards in the form of formidable ants that protect them from harm from other insects. The minor ants gather the honeydew in their mandibles and deliver it to major workers who in turn take it to the queen and larvae and transfer it to them. Ants cannot consume solid food, so, therefore, must have their food liquified to digest it. Occasionally they will attack and kill live insects, but more often they are scavengers.Foraging as far away as a hundred yards from the nest major and minor workers both seek out food by scent. 
This is usually in the form of a recently deceased insect. The ants will extract the liquid insides of the carcass and carry it back to the nest. The hard outer exoskeletons are left behind. In some cases, they may drag the entire head back to the colony where they will extract the inner tissue. They also seek out nectar from plants, honey from honeybees, syrup or sap, and plant juices. It seems they have a sweet tooth that I can relate to.
 The workers use cues in the form of biochemical pheromones to let other members of the colony know when a good food source is located and how to find it. Workers follow these scent trails to and from the food, taking resources back to the colony. Most foraging is done alone and at night, ants spotted during the day are usually scouts. Because nitrogen is an important mineral for ants, in nitrogen-poor soil, these ants will seek out urine deposits from wild animals in sandy areas.

Within many cultures ants are considered good luck, this is usually attributed to their industrious nature and devotion to the queen and colony. The Bible mentions ants more than once, and in Proverbs-Chapter 6 notes with approval, “the ant does not have a ruler to make her work. Nevertheless, she prepares her food in the summer months and gathers at harvest time. Consider the ant, we are told, and be wise”


Much can be learned from the lowly ant. While we may not welcome them in our home and seek ways to evict them as quickly as we can. We can certainly appreciate the service they are providing in their natural setting in the form of decomposition and as scavengers of dead and dying insects. And who can’t admire a large family that sticks together and supports one another? 


1 comment:

  1. Just starting to pay more attention to ants after reading Anthill (a novel by E.O. Wilson). Thank You for the carpenter ant essay. Cheers, Bernie (Jericho, Vermont)