Great tits are very nice Malcolm, but we have one or two around our garden and the incessant "Teacher! Teacher!" sometimes drives us crazy! (I'm a retired teacher hee hee!)
During the terrible wintry weather, deep snow and minus 8 degrees of frost, I swept the back lawn free of snow as best I could, then put out as much food for the poor birds as possible. It was gobbled up by so many species that we just kept putting more and more out there.
Most of our neighbours in this village did the same, and I like to think we saved many birds' lives.
The generous sploshes of bird poo down all our windows was, I reckon, their way of saying 'thank you'. Or... maybe not...