Just been outside to sort the wild birds' water bowl out and check the seed and balls.
The food was totally fine but the bowl was in desperate need of a clean and refill. Yuckerama! It's all sorted out and fresh for them now though, but I'm thinking I'll need to check the bowl more often so that it doesn't get quite so bad again... maybe a weekly job between now and when the weather starts to warm up so that it's all fresh and clean out there for them? When it's not so bitter out there, I'll try and remember to make it a daily job starting in Spring 2022 so that there aren't any hungry or thirsty birds out there.