Needle Ice

Needle ice occurs when the temperature of the soil is above 0 °C (32 °F), but the surface temperature of the air is below 0 °C (32 °F). The underground liquid water is brought to the surface via capillary action, where it freezes and contributes to a growing needle-like ice column.

Habitat: Deciduous forest. These were everywhere and many were quite large. They make walking tricky as they are hiding under leaves and collapse when you step on them.