RI, MA EHS Pest Control Blog

Ants Remember Their Enemy's Scent

Ant colonies - one of nature's most ancient and efficient societies - are able to form a "collective memory" of their enemies, say scientists.

When one ant fights with an intruder from another colony it retains that enemy's odor, passing it on to the rest of the colony. This enables any of its nest-mates to identify an ant from the offending colony.

The findings are reported in the journal Naturwissenschaften.

For many ant species, chemicals are key to functioning as a society. Insects identify their nest-mates by the specific "chemical signature" that coats the body of every member of that nest.

The insects are also able to sniff out any intruder that might be attempting to invade.

This study, carried out by a team from the University of Melbourne in Australia, set out to discover if ants were able to retain memories of the odors they encounter.

The researchers studied the tropical weaver ant (Oecophylla smaragdina), which builds is home in trees; one nest can contain up to 500,000 workers.

The team set up a "familiarization test" to allow ants from one nest to encounter intruders from another.

Over a series of trials, they placed an ant from a "focal nest" into a tiny observation arena with an ant from another nest.

After 15 of these familiarizing face-offs, the team set up a fake ant invasion. They placed 20 worker ants from the now "familiar" nest on or near the focal nest.

"These intruders were typically attacked by the resident workers," the researchers reported in their paper.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

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What are you looking at in this picture???

It is a ton of ants inside a mailbox! Imagine going to get your mail, a normal daily occurrence. This time you feel something all over your hands and when you look at your hand and mail you have a HEEBIE JEEBIE reaction with associated scream then you drop your mail. A few more convulsing twitches because you feel like they are still on you and then the whole incident is over……almost. You swat the remaining ants off the mail, grab your cell phone, and call your husband to complain about the ants.

“You are a friggin entomologist….why the heck are their ants all over our mailbox???!!!” By now you have figured out that I am the person she is talking to, this is my mailbox, and the woman is my wife Jackie. See, I get to take my work home with me! I spot baited the mailbox with some ant gel when I got home and they were gone the next day. I’m sure this is not the end of it…….

George Williams
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

Did you know that there are over a thousand different species of carpenter ant? Below are more fascinating facts about carpenter ants!

• The carpenter ant is one of the largest of all the types of ant, ranging between a sixteenth of an inch to half an inch in length.
• Queen carpenter ants have been known to grow to a massive one inch in size.
• Carpenter ants get their name from the fact that they make their nests in wood, cutting, grooving, tunneling and sanding to make a series of long tunnels, or galleries, in which they live.
• Carpenter ants are skilled carpenters and their wooden homes are perfectly smooth and rounded, sanded to perfection, and they leave no mess, no splinters, sawdust, chippings or other debris cluttering up the place.
• The carpenter ants do not actually eat the wood they excavate galleries for nesting.
• Most foraging is done at night between sunset and midnight during spring and summer months.
• Sometimes workers travel up to 100 yards from a nest in search of food.
• Carpenter ant colonies can range from several hundred ants to several thousand ants per colony.
• There can be up to 15 colonies on a given property with ants in excess of 50,000!

George Williams
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

Did you know that there are more than 12,000 species of ants all over the world! Here's some more fascinating facts about ants.

• An ant can lift 20 times its own body weight. If a second grader was as strong as an ant, she would be able to pick up a car!
• Some queen ants can live for many years and have millions of babies!
• Ants don’t have ears. Ants "hear" by feeling vibrations in the ground through their feet.
• When ants fight, it is usually to the death!
• When foraging, ants leave a pheromone trail so that they know where they’ve been.
• Queen ants have wings, which they shed when they start a new nest.
• Ants don’t have lungs. Oxygen enters through tiny holes all over the body and carbon dioxide leaves through the same holes.
• When the queen of the colony dies, the colony can only survive a few months. Queens are rarely replaced and the workers are not able to reproduce.

George Williams
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

Adetomyrma Venatrix, the Dracula Ant

For your average ant, work is grueling no matter what species you belong to. All working towards the common good and hoping the colonies lineage will be passed on, even if it takes the sacrifice of a few workers. But there is one species where sacrifice becomes a full time job.

To find it, you must search the Zombitse Forest. Yes, you are looking for ants in a forest in Western Madagascar that does not give you pause to consider the sanity of looking for something called Dracula Ants in amongst the brush which will be sure to be infested with tiny zombies. After the initial lamentations, you should be up to scowling out these tiny forest creatures.

Eventually you will find a colony of Adetomyma venatrix, the Dracula Ant. At first look you might be intrigued by the ants body form. Nearly a ‘missing link’, these ants resemble wasps more than ants. They have only one joint between their thorax and abdomen instead of three like other species of ants. They also have an elongated stinger as well as have lost the use of their eyes.

About now you are probably wondering why does this evolutionary curiosity have such a distinguished name as Dracula? Well this has to do with how they gain their nourishment. Normal ants have their larvae eat the food and pre-digest it for the workers and pass it along. But Dracula Ants are busy and need their nourishment a bit more…fluidic.

Hungary queens, drones, and workers need only chew open the head of one of their own young to find all the nutrients they could need. Their larvae have an abundance of blood, well actually, Hemolymph, which the adults of the colony can just drink their fill of.

When observed it is noted that the larvae are not fond of the arrangement in the least, as they try to crawl away when workers are present and tiny ant screams can even be detected as the adults drink their younger’s vital fluids. The survivors then pupate into adult ants and continue the cycle of work and “nondestructive cannibalism”.

By Dave McNulty
EHS Service Specialist

Pest Control, RI, Pest Control, MA

Fungus Turns Tropical Carpenter Ants Into Walking Dead
An ingeniously deadly fungus hijacks the bodies of ants for food and reproduction.

It’s like something out of a horror movie. A parasitic fungus infiltrates the body of a tropical carpenter ant, feeding on it and manipulating its body. The fungus forces the dying ant to the forest understory, an environment more conducive to its growth. The invasion of this fungal body-snatcher culminates with it sprouting a spore-laden fruiting body from the dead ant’s head.

An account of this deadly assault on tropical carpenter ants (Camponotus leonardi) by a parasitic fungus (Ophiocordyceps unilateralis) is described in the May 9, 2011 issue of the open access journal BMC Ecology.

Similar incidences of fungi parasitizing insects occur in other parts of the world. This particular case of zombie ants plays out in the forests of Thailand.

It’s a pretty gruesome affair, so if you find movies like The Thing and Night of the Living Dead too scary, now’s a good time to stop reading!

The paper’s lead author, Dr. David Hughes of Penn State University, described the ant-fungus interaction in a press release.

The fungus attacks the ants on two fronts. Firstly by using the ant as a walking food source, and secondly by damaging muscle and the ant’s central nervous system, resulting in zombie walking and the death bite, which place the ant in the cool damp understory. Together these provide the perfect environment for fungal growth and reproduction. This behavior of infected ants is essentially an extended phenotype of the fungus (fungal behaviour through the ant’s body) as non-infected ants never behave in this way.

Tropical carpenter ants spend most of their time high in the forest canopy. When they venture down to the jungle understory, they follow well-defined trails. It’s during this time that ants could get infected by fungal spores that land on their outer body.

The fungus can only complete its life cycle through the ant. Spores germinate, and the fungus penetrates the ant’s body. It proceeds to infect the entire animal, affecting its central nervous system. You can tell when a carpenter ant has been infected: instead of marching purposefully down a trail, an infected worker ant walks about haphazardly, displaying erratic behavior. Sporadic convulsions set in, causing the infected ant to fall from the canopy to the moist, cool, leafy forest understory, ideal conditions for the fungus to continue its growth.

Read more of this article, by clicking: Zombie ants: When ants become walking dead

George Williams
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

Click on image to enlarge

I am doing a pest inspection for mice and the customer shows me crazy ant trails in her kitchen and cabinets. She said they are getting into everything!!! She tried to fix it by spraying some Raid aerosol and added that they go away but come back in a few days. I told her that she is just killing scout ants with the Raid not eliminating the colony. The colony keeps sending more ants to replace the ones you sprayed.

I told her the ant colony is outside and we need to treat that. She half heartedly believed me until I showed her the massive pavement ant colony outside. She was completely amazed and said “I guess there is a reason why professionals are better.” I responded by saying anyone can “turn the screw” (AKA spray insecticide) but it takes a professional to know what screw to turn!

Mark Tremblay
Service Specialist

Pest Control, RI, Pest Control, MA