The diet consists largely of seeds from grasses and herbs as well as grain, but during the breeding season the proportion of insects rises, providing important protein-rich food for the young. In winter the Eurasian Tree Sparrow is a frequent visitor to bird feeders, where it readily takes sunflower seeds and other seed mixes, often in the company of other finches. By taking large numbers of pest insects during the summer the tree sparrow does good in the farmland, and in winter flocks can number several dozen birds.