Some species within the Arctiinae have the word "tussock"' in their common names because they have been misidentified as members of the Lymantriinae subfamily based on the characteristics of the larvae.

[2] Recent phylogenetic studies have shown that the group is most closely related to litter moths Herminiinae and the Old World Aganainae, which are subfamilies of the family Erebidae.

They also have thoracic tympanal organs for hearing, a trait with a fairly broad distribution in the Lepidoptera, but the location and structure is distinctive to the subfamily.

The insects advertise these defenses with aposematic bright coloration, unusual postures, odours, or in adults, ultrasonic vibrations.

[10] The ultrasound signals help nocturnal predators to learn to avoid the moths,[11][12] and for some species can jam bat echolocation.

Basking to accelerate digestion is common in the larval stages, and social behaviour may range from solitary to gregarious.

If disturbed, woolly bear caterpillars roll into a tight spiral or drop from their perch suspended by a strand of silk.

Even the fall webworm, an abundant and highly polyphagous tree-feeding species that has spread from North America to Asia and Europe, does not do lasting damage to healthy hosts.

The forthcoming severity of a winter may be indicated by the amount of black on the Isabella tiger moth's caterpillar—the most familiar woolly bear in North America.