Polystyrene is used in the thermal insualtion world in two versions: XPS (Extruded polystyrene) and EPS (expanded polystyrene). Both are used as thermal insulation in buildings besides cellular glass.
Ants are insects which lives in large groups and may destroy some building materials. It has been found in an extensive work of the Norwegian Institute of Public Health that ants are excaviating XPS and EPS in an important way, while leaving cellular glass in peace.
Hereunder, we give a comparison figure, extended with glass wool and mineral wool.
It is clear that cellular glass is not of interest for ants, which is a major advantage of cellular glass compared to the other thermal insulations. Some people should argue that a laboratory experiment is not the real case. The following XPS-boards, found on a jobsite in Germany in real life says everything.
The damage to the building is clear but these ants do not absorb this polystyrene. It ends as plastic contamination in the soil and is dangerous for the human health. It is amazing that this material is still allowed.