The Crambidae are the grass moth family of lepidopterans. They are variable in appearance, the nominal subfamily Crambinae taking up closely folded postures on grass stems where they are inconspicuous, while other subfamilies include brightly coloured and patterned insects which rest in wing-spread attitudes.

The Pyralidae, commonly called pyralid moths, snout moths or grass moths, are a family of Lepidoptera in the ditrysian superfamily Pyraloidea. In many classifications, the grass moths (Crambidae) are included in the Pyralidae as a subfamily, making the combined group one of the largest families in the Lepidoptera. The latest review by Eugene G. Munroe and Maria Alma Solis retain the Crambidae as a full family of Pyraloidea.

The Pyraloidea are a moth superfamily containing about 16,000 described species worldwide, and probably at least as many more remain to be described. They are generally fairly small moths, and as such, they have been traditionally associated with the paraphyletic Microlepidoptera.