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.leske's tit (Cyanistes pleskei) is a common hybrid between this species and the azure tit in western Russia. The cap is usually darker than the azure tit, and the tail is paler than the Eurasian blue tit.