Folk wisdom holds that the relative lengths of the bands of the caterpillar foretell the severity of the coming winter (5)
. Actually, the variability of the bands depends on many factors. As larvae mature, the reddish bands lengthen (2)
. Wetter weather lengthens the black bands (3)
. So while not a reliable measure, it makes some sense that onset of an early and thus longer winter will force younger and less red caterpillars into hibernation.
Caterpillars may resort to cannibalism.