Storm petrels are among the smallest of seabirds, feeding on plankton and small fish picked from the surface, typically while hovering. Their flight is fluttering and rather bat-like. The family has a cosmopolitan distribution, being found in all oceans. They are strictly pelagic, coming to land only when breeding, and nest in colonies, displaying strong philopatry to their natal colonies and nesting sites. Most species nest in crevices or burrows and all but one species attend the breeding colonies nocturnally. Several species are threatened by human activities.