About this objectSmall, agile birds, blue tits eat mainly insects. They usually nest in tree holes but often use nest boxes instead, returning to the same one year after year.
The blue tit is about 12 cm long and mainly blue and yellow in colour with a blue crown on its head. The intensity of the yellow depends on the quantity of yellow-green caterpillars the bird has eaten. It also has a crest which is raised when the bird is excited. Raising a brood of 7-8 chicks, sometimes more, is hard work. Each parent may bring food every 90 seconds during busy periods.