It will build a nest later, I guess. But its too early right now. It needs plenty of insects at the time the youngsters hatch. If they hatch too early they will starve to death. All this is becoming a problem lately. You are in the UK? I dont know how the situation is there, but here in Germany the insects are in the process of dying out. In some regions 75 - 80% are gone already. And not only single species - all of them!
That will mean the end of the other animals who depend on insects, like many birds, but also bats and some other. Which will cause a domino effect in the eco system.
But the media tells us to worry about "really important" things, like the Brexit or who becomes the chancellor, or the olympics. Yeah, right...
What can I say fantastic reply thank you very much I hope as the season goes on you will follow. Cheers mike