Colorbond roof and birds nests!!

I have only noticed recently that some native birds in our area have been making nests underneath our colorbond roof, mainly in the corners... I only noticed this as I heard some babies chirping the other day and went up the man-hole in the cieling to investigate, sure enough saw the mother bird coming in and giving them a feed! Part of me can understand that they are looking for nests anywhere they can as there are not many mature areas in our area (in a new-ish estate, about 4-5 years...

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