Long-tailed tits

These are fairly common UK birds. They are often heard with their high pitched squeak before they are seen.  

They often flit from tree to tree in flocks together. The photo shows one on our nuts a few years ago I think.

They are called log-tailed tits as they have long tails!

See https://www.rspb.org.uk/birds-and-wildlife/long-tailed-tit .