Pygmy Owls are members of the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Glaucidium. They belong to the typical owl

Typical owl

True owl or Typical owl are one of the two generally accepted families of Owls, the other being the barn owls . The Sibley-Ahlquist taxonomy unites the Caprimulgiformes with the owl order; here, the typical owls are a subfamily Strigidae...

 family Strigidae, one of the two generally accepted living families of owls.
The genus consists of about 26 to 35 species distributed worldwide. The exact number of species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 is somewhat disputed.

These are mostly small owls, and some of the species are called "owlets". Most pygmy owl species are nocturnal and hunt mainly large insects and other small prey.

• Eurasian Pygmy Owl
  Eurasian Pygmy Owl
  The Eurasian Pygmy Owl, Glaucidium passerinum, is the smallestowl in Europe. These owls are a dark reddish to greyish-brown, with spotted sides and half of a white ring around the back of their neck....
  
  , Glaucidium passerinum
• Collared Owlet
  Collared Owlet
  The Collared Owlet is a species of owl in the Strigidae family.It is found in Afghanistan, Bangladesh, Bhutan, Brunei, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Pakistan, Taiwan, Thailand, and Vietnam....
  
  , Glaucidium brodiei
• Pearl-spotted Owlet
  Pearl-spotted Owlet
  The Pearl-spotted Owlet is an owl which breeds in Africa south of the Sahara. This species is a part of the larger grouping of owls known as typical owls, Strigidae, which contains most species of owl. The other grouping is the barn owls, Tytonidae.Pearl-spotted Owlet is a common and easily seen...
  
  , Glaucidium perlatum
• Mountain Pygmy Owl, Glaucidium gnoma
  • Guatemalan Pygmy Owl, Glaucidium (gnoma) cobanense
  • Cape Pygmy Owl, Glaucidium (gnoma) hoskinsii
• Costa Rican Pygmy Owl, Glaucidium costaricanum
• Cloud-forest Pygmy Owl, Glaucidium nubicola
• Andean Pygmy Owl, Glaucidium jardinii
• Yungas Pygmy Owl, Glaucidium bolivianum
• Colima Pygmy Owl, Glaucidium palmarum
• Tamaulipas Pygmy Owl, Glaucidium sanchezi
• Central American Pygmy Owl, Glaucidium griseiceps
• Subtropical Pygmy Owl, Glaucidium parkeri
• Amazonian Pygmy Owl, Glaucidium hardyi
• Pernambuco Pygmy Owl, Glaucidium mooreorum
• East Brazilian Pygmy Owl, Glaucidium minutissimum
• Ferruginous Pygmy Owl
  Ferruginous Pygmy Owl
  The Ferruginous Pygmy Owl is a small owl that breeds in south-central Arizona in the USA, south through to Mexico, Central America and South America to Bolivia and Argentina. Trinidad, as well as other localities, have endemic subspecies of this owl...
  
  , Glaucidium brasilianum
  • Ridgway's Pygmy Owl, Glaucidium (brasilianum) ridgwayi (species or subspecies)
  • Tucuman Pygmy Owl, Glaucidium (brasilianum) tucumanum (species or subspecies)
• Pacific Pygmy Owl, Glaucidium peruanum
• Austral Pygmy Owl, Glaucidium nanum
• Cuban Pygmy Owl, Glaucidium siju
• Red-chested Owlet
  Red-chested Owlet
  The Red-chested Owlet is a species of owl in the Strigidae family. It is found in Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Equatorial Guinea, Gabon, Ghana, Kenya, Liberia, Rwanda, Sierra Leone, and Uganda.Very small owlet...
  
  , Glaucidium tephronotum
• Sjostedt's Barred Owlet, Glaucidium sjostedti
• Asian Barred Owlet
  Asian Barred Owlet
  The Asian Barred Owlet is a species of true owl, resident in northern South Asia and SE Asia . Its natural habitat is temperate forest....
  
  , Glaucidium cuculoides
• Javan Owlet
  Javan Owlet
  The Javan Owlet is a species of owl in the Strigidae family.It is endemic to Indonesia.Its natural habitat is subtropical or tropical moist lowland forests.-References:...
  
  , Glaucidium castanopterum
• Jungle Owlet
  Jungle Owlet
  The Jungle Owlet or Barred Jungle Owlet, Glaucidium radiatum, is found in India and the dry zone of Sri Lanka. The species is often found singly, in pairs or small groups and are usually detected by their calls at dawn and dusk...
  
  , Glaucidium radiatum
• Chestnut-backed Owlet
  Chestnut-backed Owlet
  The Chestnut-backed Owlet, Glaucidium castanonotum, is an owl which is endemic to Sri Lanka. This species is a part of the larger grouping of owls known as typical owls, Strigidae, which contains most species of owl. The other grouping is the barn owls, Tytonidae.-Identification or Description:The...
  
  , Glaucidium castanonotum
• African Barred Owlet
  African Barred Owlet
  The African Barred Owlet is a species of owl in the Strigidae family. It is found in Angola, Botswana, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Kenya, Malawi, Mozambique, Namibia, Somalia, South Africa, Swaziland, Tanzania, Uganda, Zambia, and...
  
  , Glaucidium capense
  • Ngami Owlet, Glaucidium (capense) ngamiense
  • Scheffler's Owlet, Glaucidium (capense) scheffleri
• Albertine Owlet
  Albertine Owlet
  The Albertine Owlet, Glaucidium albertinum, is a species of owl in the Strigidae family. It is found in Democratic Republic of the Congo and Rwanda. Its natural habitat is subtropical or tropical moist montanes. It is threatened by habitat loss....
  
  , Glaucidium albertinum
• Chestnut Owlet
  Chestnut Owlet
  The Chestnut Owlet is a species of owl in the Strigidae family.It is found in Cameroon, Democratic Republic of the Congo, Ivory Coast, Liberia, and Uganda.-References:...
  
  , Glaucidium castaneum

The supposed prehistoric species "Glaucidium" dickinsoni is now recognized as a burrowing owl

Burrowing Owl

The Burrowing Owl is a tiny but long-legged owl found throughout open landscapes of North and South America. Burrowing Owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation. They nest and roost in burrows, such as those excavated...

, probably a paleosubspecies providentiae.