They are generally thick-bodied and hairy, often with bright colors, velvety textures, and intricate markings.

Saturniids include some of the largest winged insects on Earth, with wingspans ranging from roughly 2.5 cm to nearly 30 cm (1 to 12 inches), such as the Atlas moth ( Attacus atlas ) and Hercules moth ( Coscinocera hercules ).

Male saturniids possess long, broad, feather-like antennae designed to detect female pheromones from over a mile away.