Where to see them Blue tits are common in woodland, hedgerows, parks and gardens. They're widespread and found across the whole of the UK with the exception of some Scottish islands. When to see them All year round. What they eat Insects, caterpillars, seeds and nuts. Population Europe UK breeding* UK wintering* UK passage* 20-44 million pairs 3,535,000 territories 15 million birds - * UK breeding is the number of pairs breeding annually. UK wintering is the number of individuals present from October to March. UK passage is the number of individuals passing through on migration in spring and/or autumn.