For the last couple of weeks we've been privileged to have flocks of seven or eight of these little birds in our tiny garden several times a day, feeding on fat balls and coconut feeders - aren't they gorgeous? Wish I'd taken the photo but sadly, they move so fast my camera wouldn't catch them and they are SO nervous that I'd never get near enough. They're one of our tiniest birds, though - if not the tiniest - not sure if Goldcrests are a tad smaller and Coal Tits aren't too far behind. They do look bigger because of their long tails but if you look closely, you can see they're nothing but a little ball of fluff on the end of a stick, lol :) Unfortunately, they have a really high mortality rate in Winter and especially when it's as cold as it has been. They have so little surface area that they lose heat fast, even though they sleep huddled together to keep themselves warm.
This one may give you an idea of just how tiny they are…