Frost was originally the hoarfrost made real.
Ideal conditions for hoarfrost to form on snow are cold clear nights, with very light, cold air currents conveying humidity at the right rate for growth of frost crystals.
After a storm, the temperature drops rapidly and, due to the excess humidity, hoarfrost forms on the surface of the snow.
At this point further removal of heat would result in water vapor condensing into liquid water fog or, if below freezing point, solid hoarfrost.
The resonant frequency decreases with increasing accretion (additional mass) of ice, hoarfrost, freezing fog, freezing drizzle, rime, or wet snow.
They subsist off lichen found in hoarfrost as well as eating mushrooms and other fungi found in ice caves.
