February 2014 Archives

Small black ants (Michael)

Dear Ant Experts,

I read with interest your comments to Anna's invasion of ants.

I have had to control these ants from entering the house using diluted permethrin. Of course I have observed their behaviour after spraying. Those that were not killed gathered in clusters. I noticed that in the train line each ant touched the face of the other as they passed. Could you explain are they passing on some chemical or are they communicating somehow to join the cluster so an alternative safe route can be determined.

I would greatly appreciate your comments.


Hi Michael,

What you have been observing may be either one of two behaviors often seen in ants: 1. Mouth-to-mouth trophallaxis. Ants feed other colony members with this behavior. Food is often stored in the crop, the social stomach, and then regurgitated if it needs to be distributed among other colony members. 2. Chemical communication. Ants communicate with each other through chemical signals. These are perceived with their antennae. When seen under a microscope or magnifying glass, it almost looks like ants scan each other with their antennae. This might happen once ants consumed a toxic bait because they may smell different to their colony mates.

All the best,
Steffi Kautz and the AntAsk Team