Ant sounds vary from family to family and include some that produce sounds by stridulation, which is defined as the act of producing sound by rubbing together certain body parts. These are usually high-pitched chirps made by rubbing together specialized body parts on the abdomen called files and scrapers. Stridulations are sometimes heard, but most often felt, the vibrations being detected by sensitive receptors on the legs.
Soundclip of Singing Ants
Communication is key
The sounds are used in different ways, depending on the species. A great example of the use of sound is when a worker ant has been trapped somewhere. Maybe through the collapse of a tunnel or chamber – blocking all the exits. The ant can use sound as a distress call, signaling their location to the other workers through the walls.
So back to Bernie’s suggestion, we located the nest of Paltothyreus tarsatus the African Stink Ant, a large black ant that it very common in the bush here. While we were placing the microphone over the entrance to the nest, we saw an ant steadily making its way to the nest with some food in its mandibles, and we quickly placed a few large stones around to the microphone to seal off the entrance.
It immediately started trying to move one of the stones and at the same time started stridulating, obviously indicating to the rest of the underground colony that there was a problem. Worker ants close to the entrance replied with soft squeaking sounds and then several soldier ants arrived and quickly moved one of the stones to open up the entrance and then attacked my microphone. Both the squeaking of the workers and the chewing sounds of the soldiers can clearly be heard in the accompanying sound clip (ever better if you listen through a set of headphones).
We then moved the rest of the stones and the microphone to once again allow free access to the nest and all of the ants made their way back into the underground chambers. As Bernie told me, this is natural behaviour and the few seconds of recording this amazing behaviour actually caused them no harm.