The Eurasian blue tit (Cyanistes caeruleus^[2] or Parus caeruleus^[3]) is a small passerine bird in the titfamily Paridae. The bird is easily recognisable by its blue and yellow plumage, but various authorities dispute their scientific classification.

Eurasian blue tits, usually resident and non-migratory birds, are widespread and a common resident breeder throughout temperate and subarctic Europe and western Asia in deciduous or mixed woodlands with a high proportion of oak. They usually nest in tree holes, although they easily adapt to nest boxes where necessary. Their main rival for nests and in the search for food is the larger great tit.

The Eurasian blue tit prefers insects and spiders for its diet. Outside the breeding season, they also eat seeds and other vegetable-based foods. The birds are famed for their skill, as they can cling to the outermost branches and hang upside down when looking for food.

(From Wikipedia, March 2015)