Often known simply as "blue tit"
Blue Tits have a distinctive blue crown edged with white, and a narrow black stripe through each eye; cheeks are white. Underparts are yellow, and the back is greyish-green. The wings are blue with a white wingbar. The tail is also blue.
Sexes similar but females are duller.
Young are similar but with yellow cheeks instead of white.
They are welcomed by gardeners because they eat aphids. Their small size allows them to hop up the stems of plants and hang upside down while seeking the pests They also feed on peanuts.
They readily adopt nest boxes supplied to them. Their nestlings leave the nest before they can fly, and are vulnerable to predators such as cats.