Ants in your house or yard: June 2011 Archives

Dear AntWeb,

We think there are ant nests in our home but would like to confirm with you first. Please bear with us as we describe the whole situation below.

Background:
About 3 weeks ago, one morning we saw a pile of sawdust at a very small ridgeline crack where the base of the bathtub meets the floor at (on the outside of the tub, there are separate bathtub and shower stall in our bathroom). There are also about 5 winged ants sluggishly crawling around on the floor. We thought they could be termites so we check the pictures and verified that they were not termites (pinched waist), probably carpenter ants. We killed the ants and removed them along with the sawdust pile. Three days later, we saw the same things, sawdust pile and sluggish winged ants at the same location. This time, after we killed and removed the winged ants and sawdust, we used the 'Raid Ant & Roach spray' at the crack and all along that area.

A few days passed and there were no more ants so we thought all the ants were gone (mistakenly). But we still used the same Raid Ant spray evryday to make sure. Then 2 weeks ago, one morning, we saw about 50 winged ants, some dead, some sluggish, on the bathroom floor and along the window sill. We started to spray more but every morning, we still saw them, but less (about 30). We sprayed at the crack, around this area and at the window sill. After reading about the winged males/females mating, we're really worried.

Questions:

1. Does this mean we have a (or more) carpenter ant colony nesting inside somewhere our bathroom?
2. If there are ant nests in our house, then why do we only see the winged ants (supposedly out for mating), but we do not see the wingless worker ants inside the home?
3. Did the winged male ants die right after mating? Or they died because of the 'Raid Ant spray' that we used at the crack and window sill?
4. What are your conclusion and suggestions on how to resolve the ant problem.

Please let us know. Your responses are much appreciated. :)

Thanks so much for your help,
Homeowners with Ant Problem


*****
Dear Homeowners with Ant Problem,

Although most ants are happy living outside, there are a few pest ant species that find living in our homes preferable. Unfortunately this includes carpenter ants!

If what you are seeing are carpenter ants (or termites - check out this post to tell the difference) it is important that you contact a pest control group that is familiar with these insects to have them eradicated. As these insects can cause structural damage to your home it is important that you have an experienced pest control expert exterminate them.

For general tips about controlling ants in your home, please check out this previous post here.

One thing to note that since ants live in colonies, unlike most other home pest insects, using insect killing sprays will not really fix the problem. When you spray the ants you are seeing, you are only making a dent in the colony as a whole. You need to kill the queen, which is deep in the colony, to insure the death of the whole ant colony.

Regarding your specific questions, I will address each below:

Q1. Does this mean we have a (or more) carpenter ant colony nesting inside somewhere our bathroom?

A: This is likely, although they could be living outside of your home and only venturing in. But since you are seeing them in large numbers, I suspect they are living in your home.

Q2. If there are ant nests in our house, then why do we only see the winged ants (supposedly out for mating), but we do not see the wingless worker ants inside the home?

A: Although carpenter ants like living in our homes, they do not necessarily like to eat the same food we do, which is why you rarely seem them foraging in your home. The sexuals (virgin queens and males) are trying to find a way out to go on their mating flight.

Q3. Did the winged male ants die right after mating? Or they died because of the 'Raid Ant spray' that we used at the crack and window sill?

A: I doubt the ants have had a chance to mate yet (they usually require a mating flight or swarm). They are likely dying due to the insecticide.

Q4. What are your conclusion and suggestions on how to resolve the ant problem.

A: As mentioned above, it is good idea to contact a pest control specialist who is familiar with exterminating carpenter ants and termites.

Best of luck,
Corrie Moreau & the AntAsk Team


Hello,
I've been feeding some ants on my desk which I believe to be Tapinoma sessile. I tracked them quite a long way to the front door of my house. Recently I discovered that some of the ants are coming from the opposite direction from my window which is halfway around the house. Is there a way to tell if they are from the same colony?
I've read that T. sessile is very tolerant of other ants so I don't expect any fighting. I tried to see if the ants coming from one way would go the other way. This leads me to my next question, would ants from the same species but different colonies be able to recognize each other's pheronomes as if it were their own?

Thanks,
Rex


Hi Rex!

Thanks for contacting us at AntAsk! To tell whether ants are from the same colony, I would suggest that you carefully collect one ant from one of the groups and place it in the other group. Of course, if fighting takes place, the ants were from different colonies. But also if the ants start inspecting each other carefully with their antennae and might even pull each other at the mandibles, this suggests they are from a different colony. If the ants act as nothing has happend and the experimentally introduced individual just runs with the others, they might indeed be from the same colony.

Researchers often use behavioral observations to determine colony boundaries. Other tools are the analysing cuticular hydrocarbons and/or genetic markers such as microsatellites. Social insects such as ants use low-volatile chemicals (usually hydrocarbons) that are present on the cuticle to distinguish nestmates from foreign individuals. If the hydrocarbons of two ant colonies are very similar, which might be due to the fact that the colonies are related to some extend, ants might have a hard time to determine who is a nestmate and who is not.

I hope this answers your questions!
All the best,
Steffi Kautz & the AntAsk Team

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