2-phenoxyethanol is the chemical name of a solvent that helps ink dry quickly, but also mimics an ingredient in termite "trail pheromone;" it helps them follow each other.
It's used in both blue and black ink, and from either Bic or Papermate pens. Its primary use is in middle school science projects, to teach kids how pheromones work. You use this pen to write your name on a piece of paper, then drop some termites on there, and watch as your name is spelled in ants.
The Trail Pheromone of the Termite, Trinervitermes trinervoides. Tschinkel, Walter R.; Close, Peter G. (1972). J. Insect Physiol. Vol 19. pp. 707-721.
^This 1972 study says that "activity loss from filter paper is approximately exponential with a half-life of about 2 hr" in case you were wondering.
The Identification of 2-Phenoxyethanol in Ballpoint Inks Using Gas Chromatography/Mass Spectrometry – Relevance to Ink Dating. Laporte, Gerald & D Wilson, Jeffrey & Cantu, Antonio & Amanda Mancke, S & L Fortunato, Susan. (2004). Journal of Forensic Sciences. 49. 155-9. doi:10.1520/JFS2003217
^And why is this article published on the ASTM website? And with all the references listed as working for United States Secret Service, Forensic Division? Because you can tell how old a document is by measuring the amount of this chemical that is left in the ink.
Just pheromone things - "Seducin" - Some male cockroaches and crickets produce a pheromone called seducin from their bodies, on which the females nibble during copulation. This pheromone is an aphrodisiac.