What are these BIG black ants in my house?
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| carpenter ant |
In early spring or late winter people often encounter these large black ants in homes. These big ants are different than the more common small, brown "nuisance ants" that plague kitchens. The big ants are called carpenter ants (Camponotus spp.) and unlike their smaller cousins, nest above ground in cavities. Nest building and cavity expansion by these large, powerful ants can cause damage if nests occur in our homes.
Most of the ants you find in homes are small, less than 1/4", and brown. There are several species of small brown ants that can nest in our home's walls or nearby soil and enter homes in search of food and water (see House Ants for identification and control). Nuisance ants are just that, a nuisance. They won't damage your home and pose no health threat of any kind.
There's another ant, however, that occasionally is found in homes that is much bigger (1/4"-5/8"), darker in color, nests in the walls, floors and ceiling and can cause significant structural damage if not treated properly. People's first reaction often is "what are these BIG black ants in my home?" These are the carpenter ants and they can destroy the materials (structural wood, insulation, sheathing and so forth) that surround their nests. Thousands of dollars in home damage can be caused by a single carpenter ant nest as it grows.
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| Winged (left) and wingless (right) carpenter ants |
Carpenter ants normally forage outside for food and water. Foraging ants will therefore move back and forth between their nest in a house and their hunting/foraging grounds outside. Carpenter ants are scavengers and predators taking whatever food they can find. The only time they normally enter the living space of homes is in late winter and early spring before their food sources develop outside. Therefore, if you find more than a few of these big black ants indoors, especially in spring, that's a pretty sure sign that you have a nest somewhere in the home. Don't be concerned about carpenter ants you find outdoors at any time of the year unless they are trailing into your home.
You may also find carpenter ants with wings (see photo above). These are the so called "reproductives" that start new colonies. Since this stage can easily shed their wings the ants you find indoors may have actually flown in through an open window or door.
Once you confirm the workings of a carpenter ant nest in your home (see Inspecting Homes For Carpenter Ants) plan to treat the whole house (see links below). There is no need for "periodic maintenance treatments" advocated by some pest control companies, treat only when you know for sure that there's a problem.
Use the following articles to treat carpenter ant nests around your home. If you are handy you can probably do most of this work yourself, except perhaps repair of existing damage. If you are not so handy take a look at the article below about hiring pest control services.
Comments
Once this flight/migration has finished in a few days inspect around the house to see if ants are trailing to and from the house. If they are this means there's a nest in the house and needs to be treated. If not, the nest is likely located outside and does not not to be treated. See the Related Articles for more info.
Contact me at livingwithbugs@gmail.com and we can discuss this. The options are too involved to list here. Also, take a look at http://www.livingwithbugs.com/carpenter_ants.html for some background info.
Jack DeAngelis
This many ants probably means there's a nest in the walls or subfloor. You can control carpenter ants yourself but it can be a lot of work. Most people opt to hire a pest control company (there are suggestions on our site at http://www.livingwithbugs.com about hiring a PCO). Contact me at livingwithbugs@gmail.com if you want to discuss this.
Jack DeAngelis
I think this is more than a coincidence and probably means there's a carpenter ant nest in the roof. Take a look at the carpenter ant control options I've post at our 'Bugs site or contact me at livingwithbugs@gmail.com if you want to discuss this further.
If the ants are more than 3/8" they are very likely carpenter ants. Tell the management so they can have them treated. If you are concerned about pesticide exposure during treatment tell them this as well. If you live on the top floor the nest(s) is probably in the roof and the cause could be tree branches that have been allowed to touch the roof giving the ants an avenue on which to forage.
Contact me at livingwithbugs@gmail.com if you have questions.
This time of the year you can't really set a number. It is better to look outside for ants trailing between the house and yard where they forage for food. See the articles cited above for details about inspecting for carpenter ants. Contact me at livingwithbugs@gmail.com if you have questions.
Then tonight I see another one outside my pantry. I figure they're scouts since I've only seen one at a time. But would these still be carpenter ants if they appear as regular black ants but just significantly larger and are there any concerns: biters, stingers?
Thanks, Brian
I just had my house treated for carpenter ants. Part of the house is a two story structure. The tech said there was no need to treat the second story as the ants travel down at night to their nests. He did finally treat one wall as I have seen quite a few ants come from that wall. Why wouldn't you treat all four walls upstairs like they did downstairs? Is this customary or is this just a story to get out of treating the upstairs?
Thank you, Zema
I have started to see the carpenter ants coming in (two yesterday on level 4 and one today on level 3). Are they coming in from the roof? The rooftop patio has a wooden floor (like a deck) on top of a metal sheet.
I had some trees in wooden barrels but they all died over the winter. I thought they dried out because of snow and wind. Could the carpenter ants be eating them to die?
I have an exterminator coming in. Please, help me where to look for htem. I am terrified of them. They are 2.5 cm! The exterminator (Orkin) said it would take up to a year to get rid of them, probably over 4 or more visits.
Thanks, Laurie Decker
The previous owner did a treatment through a company Terminite and i do have a 1-year warranty.
A month or so ago, i did start noticing 1-2 ants a day and couple of days back when i came home in the evening, i must have flushed out 20-30 ants, the next day almost a 100 and yesterday about 30 odd.
All of these ants appear from nowhere in my kitchen and family room.
I did notice 1 odd ant total so far in the basement and maybe a couple on the 2nd floor so far.
I did notice a dead queen ant in one of the 2nd floor bedrooms.
I have arranged for a treatment again from the same company.
Could you advise what i need to tell them or insist upon? Does the whole house need to be treated?
Thank you!
We have been here for 10 years now and cannot get rid of them. Once we cut down some trees in the back yard and were absolutely infested for a year. Once we cut out a wall to install a window and the whole interior of the wall seemed to be a mummified nest.
They seem to appear in February. Last year we moved out of the kitchen for a month and kept most of our food in the living room. I sprayed raid in there every day. Then we ripped our entire kitchen out and replaced everything except for the window and we were out of the kitchen for another month. I thought this would surely get rid of them until last week.
I opened the door to the garage which is off the kitchen and the threshold was covered in ants 50-100. I tried stomping them but they scattered fast. Since then I have found over 100 in the kitchen. (Typically 10-20 per day.) what am I going to do? What is wrong with my house?