bug on landing

bug on landing

Observation - bug on landing. Description: the front smooth end extended out and retracted fast when aware of movement, had photographed a moth then a day later saw this, the moth might have been xanthorhoe fluctuata, would this be a stage of it's hibernation?

the front smooth end extended out and retracted fast when aware of movement, had photographed a moth then a day later saw this, the moth might have been xanthorhoe fluctuata, would this be a stage of it's hibernation?