Pine tree resin
This resin is organic and not heat treated like commercial use resin. 
 
It is suggested for use by Formica Rufa and Formica Rufibarbis as well as the possible use of other Formica found in woodland like Sanguinea.
 
Research has concluded that tree resin is used by the ants to place around their nest entrances, when used in conjunction with their formic acid it has 3 main uses;
the resin provides antiseptic and antibacterial properties for the nest to prevent diseases
the resin sterilises the ants as they b-line for it when entering and leaving, like a big block of alcohol gel
it can be used as a "venting" block for the ants to discharge excess formic acid that would otherwise be release into their nest. Especially vital for species in captivity where threats are minimal and the acids use is rare.
 
We provide a small bay of around 5 grams which it plenty for your colony.