The activity period for A. phalerata varies regionally, from April to September in the southern parts of its range, and from May to August in the northern areas.

Similar to cicadas, tiger moths possess tymbals on their metathorax, which they use to produce high frequency clicks.

Throughout its life cycle, which includes the stages of egg, larva (caterpillar), pupa, and adult, A. phalerata undergoes complete metamorphosis.

As caterpillars, they feed on a variety of vegetation including grasses, garden crops, and low-growing plants such as Trifolium (clover), Spartina (cordgrass), Taraxacum (dandelion), and Plantago (plantain).

Despite their warning colors, harnessed tiger moths are preyed upon by bats, which rely on echolocation to hunt.