From the bluetits’ perspective, an apricot tree full of aphids is a great blessing. That’s the virtuous reason why this human does not spray it with insecticide, but he also has a care for Mrs T’s tadpoles, which are now quadrupeds. And the tree could not be sprayed properly without a flying drone; it’s in a really awkward position.
That’s the lazy reason for not spraying.
The foliage means that unless you know where and when to look, you won’t see juvenile blackbirds or robins, sitting tight till parents come. You will hear and then see bluetit babies, since they travel around with the rest of the family, chattering away between beakfuls of greenfly.
Mrs T witnessed the return of our family of bluetits at coffee time yesterday, and went on her way rejoicing.