[2] They nest in colonies on cliffs or in short trees or shrubs, seldom on the ground.

[2] These birds feed on small fish which they catch by dipping their bills beneath the surface while flying; they do not plunge dive.

[3][4][5] The genus was introduced as Anoüs by the English naturalist James Francis Stephens in 1826.

[9] A molecular phylogenetic study published in 2007 found that the genus Anous was a sister group to a clade containing the terns, gulls and skimmers.

The authors proposed that the noddies should be merged into a single genus Anous and that Procelsterna should be considered as a junior synonym.