Saturday, August 29, 2009

Ant Swarm

Here’s a lovely swarm of ants coming out of crack beside the barn door. The winged ants are the reproductive individuals and will fly off to mate. The female then lives on to create a new colony. When I was a kid living in urban areas, people used to band together to destroy swarming ants, mistaking them for termites. I have a vivid image of a circle of adults in the middle of a lawn, beating at swarming ants with brooms and shovels, splashing out gasoline like they were having a champagne party, and finally throwing in cigarettes until the gas ignited. They’re behavior made sense to me as an eight year old, because I knew that’s the way the villagers in the movies always acted when they cornered the monster in the castle. Now I wonder how they managed to act that way without someone being hurt or killed. Despite these early lessons, I still love ants, swarming or otherwise.

This is a species of Crematogaster ant. That heart shaped rear end, called a gaster, is often raised above the body when the ant is agitated. At the tip of the gaster is a functional sting that dispenses a drop of caustic liquid used for defense. This ant often carries larvae and pupae to an elevated location for final transformation to adult form. This is the ant most commonly found in Bluebird boxes, usually accompanied by a pile of white pupae.

The workers are quite adamant that the winged individuals fly off and take care of business. Winged males and females will be bitten and prodded until they take off. This is a mixed bunch, the winged males being smaller than the females and the workers being without wings.

This is a female, or queen, resting on top of my filing cabinet. She carries an overly large gaster intended to lay eggs for the next few years. She’ll fly first and the males will follow.

The workers aggressively defend the area around the swarm. Crematogaster is showing this Allegheny Mound Ant who’s boss.


  1. Steve, I'm going to test your ant knowledge (my own is slim to none!). Every year we get some flying ants inside our house, and they either bite or sting, and they cause quite a painful pinch, followed by some itching. They are maybe a little over 1" long, and constantly flit about. I've never seen more than a few at a time, but I've been "bitten" several times, and I'm not terribly nice to them. Have you ever encountered such an ant before?

  2. Heather - My first reaction, based on the size and behavior of this insect, is to say it's not an ant. I would guess it's a type of wasp. Ants and wasps are part of the same Order, Hymenoptera, and share a lot of the same body characteristics. There are a few wasps that look more like ants than some ants do. A flying ant's basic instinct is to head for open sky where mating occurs. Inside a house they usually go to a window or light and stay there. When these guys pay another visit, maybe you can get some photos and we can make a positive ID.