Formica aquilonia or Red Wood Ant is a species of ant commonly found in the area where I live. The ant colonies are easily recognizable by the large mounds that they build out of debris from the pine forests they inhabit. The mounds also tend to be clustered together. I’m not sure what is the relation between the mounds, but the activity between them can be so frequent that “ant highways” or noticeable paths form on the forest floor. Ants are in the Family Formicidae meaning they give off formic acid when defending a territory through biting or spraying. Formic acid happens to be highly corrosive to some piezo transducer materials. This I know because one of the contact mics I used to record the ants was unprotected and went bad after about 15 seconds after I placed it on a mound.
The recording method here is something of an intervention and is not scientific in any way. If anything it is quite a provocation for the ants as I place the mics on the surface of the mound. They take it as a foreign object (which it is) and attack it. So the sound is a combination of biting, scratching and walking on the contact mics. To add some variation I used two different kinds of piezos and attached some thin brass wire to the discs. I do my very best not to harm the ants or their mounds especially since they are under a mild form of environmental protection due to threats from pollution.