Termites follow the ink produced by Scripto, Papermate and Bic brand pens because the ink smells like a specific termite trail-marking pheromone. Termite scouts lay these pheromone trails to lead other termites to sources of food.
Pheromones are chemical scents undetectable to humans. Termites rely on scent to communicate because they are blind. The drying agents in pen ink closely mimic the termite pheromone that indicates other termites should "follow this to food."
Termite-trail pheromone chemicals are called unsaturated aliphatic alcohol. The chemicals in the pens are called glycol derivatives.
The pheromones lose their scent within 15 minutes. This is about the same amount of time a termite will follow an ink line before it wanders off. Soldier termites follow an ink trail longer than workers do.
An ink line on a piece of paper can be briefly used to attract termites. It can also show students the power of pheromones.