Ant Identification

Ant Identification


We are Seattle’s #1 Ant Control: offering highly effective pest solutions that meet your needs for safety and effectiveness. Customercentric and referral driven.


On this page:

  • Carpenter ant identification
  • Odorous House ant identification
  • Pavement ant identification
  • Moisture ants identification
  • Ant identification based on size and color
  • How you can help us get rid of your ants


The four most common ants we are asked to identify, with wings or not, are listed above. There are many more kinds of local ants, they are just not as common. If you don’t see your ant named above, browse lower to a fuller list of local ants. For a guide to identifying winged ants: see the link: Flying Ants because the information below will not apply


Carpenter ant identification

Carpenter ants(Not to scale – but close) More Carpenter ant info

These ants are often seen inside during the spring. They may forage for sugar or moisture for a few weeks and then when their real food sources develop outside (they eat aphid secretions and other insects) they seem to vanish.  This is a clear indicator of nesting activity in the home.

There are over a dozen different species of Carpenter ants. The most common is a very dark brown. They may however be brown with a very dark red middle section, black, and sometimes completely red.

Unlike most ants that you will encounter, Carpenter ants come in multiple sizes.  The largest number of ants in a colony, and all the ants when the colony is young, will be ‘minor’ workers, that is, workers of a smaller size. As the colony matures it produces medium size and ‘major’ size ants.

A really good indicator that you have Carpenter ants is when you see ants that look like each other, occur in the same areas, but vary in size.

A visual guide to identifying a carpenter ant worker by it’s shape can be found on the carpenter ant link noted above.


Odorous House ant identification

Odorous House Ants(1/16th of an inch long. Photo not to scale – enlarged 6 or 7 times)

More OHA info here

Tiny ants: usually seen in the kitchen, sometimes in the bathroom, especially in the spring or when food is left out: 9 times out of 10, tiny dark colored ants in these areas are odorous house ants (OHAs). They will range from ‘super tiny’ to slightly larger but still ‘very little’ and are usually dark brown to black.  The treatment process for a number of very small ants is be the same and you should check out our link to  Swarms, if they occur, often happen between May and July. (Swarms involve flying ants.)


Pavement ant identification

Pavement Ants More Pavement ant info here

Little ants, although typically at east twice the size of odorous house ants, usually seen outside around pavers, under or around walkways, and often seen where driveways meet garages. These ants are seen inside sometimes, around the edges of garage floors or in basement or slab homes, coming up around cracks or crevices in the floor.  They range in color from a reddish brown to a dark brown / black and are noted for making small mounds of sand or fine dirt particles. If you have mounds of sand or fine dirt showing up between pavers, or slab joints, you probably have pavement ants. Unlike OHAs, these guys show up often in areas of a home other than kitchens and bathrooms. They do not respond well to baiting.


Moisture ant identification

Moisture Ants (Winged male reproductives, very close to scale) More info here

In our area we lump two different kinds of ants together, because of their nesting habits, and call them ‘moisture ants’. Moisture ants often infest homes for years before being noticed. When they are noticed, it is typically because someone is repairing some rot or water damage and the reddish brown, smallish sized ants, are found in the area of damage. A fair number are found in July and September when their nests produce swarms of ants (activity from winged ants) inside a home.  The winged female swarmers are a reddish brown color and are much larger, about the same size as Carpenter ants, and are sometimes mistaken for those ants. The winged males are tiny and dark brown to black, about the size of a gnat or a large mosquito.


Identifying ants by size:

Since almost all ants are little in comparison to us, lets set some size parameters that should be easy for all of us.

Carpenter Ant widthIf you stack pennies on top of each other you will get 16 to 17 pennies in an inch high stack. All the ants noted below are sized by the thickness of a penny. So the thickness of a penny is about a sixteenth of an inch wide.

Tiny: Ants as small as 1 to 2 pennies are thick:

Big Headed ants, Thief ants, Pharaoh ants, Rover ants, some species of Odorous house ants, Ghost ants, Large yellow ants, and Little Black ants. (Yes, there is a little black ant species named: Little Black ants. All of these ants are about a 1/16th of an inch long.

Little: From 2 to 3 pennies thick:

Acrobat ant, Argentine ant, Cornfield ant, Pavement ants, White Footed ant, and some species of Odorous House ants. These ants are about an 1/8th of an inch to just over an 1/8th.

Medium: From 3 to 4 pennies thick:

Velvety Tree ants, Field ants, Carpenter ants start at this size, at least some species, and even the minor workers of the larger species. Up to a quarter of an inch long.


Carpenter ants may be from 4 pennies to 9 pennies wide. If you are seeing ants that range in size but all look the same, same color and shape- you probably have Carpenter ants. If they are all exactly the same size, you may have some species of Thatching ants.


Identifying ants based on color:

Ant color is based on the same factors that govern hair color in humans. If you have more pigment the color will appear darker.  How many shades of brown hair do humans have? Combine that with the fact that there are almost always more than one species of each type of ant – like with flowers.  The color of an ant is the least reliable method of identifying it.


How you can keep from getting ants

There are actually a number of things that can be done to help get rid of carpenter ants, and other types of ants too. Most of these steps will also make any service designed for controlling carpenter ants more successful with less use of pesticide.

Please visit our page: Ant Prevention to learn how to make your treatment more effective.


Comments are closed