Ever since I realised how many blackbirds, honey-eaters and pigeons make nests in the yard and garden every year, I've been taking the lint from the clothes-dryer filter and leaving hanks of it draped around on branches and bushes instead of throwing it away.
I always feel a bit mad doing this, and it makes the garden look extremely strange. But then in late summer when I haven't used the dryer for months and am cutting back the overgrowth, or in midwinter when I'm doing the pruning proper, it always makes me glad that I did it whenever I come across yet another one of these from the last nesting season, the way I did today:

'Gaston Bachelard, writing about nests in
The Poetics of Space, quotes from Jules Michelet's
L'Oiseau (1858): "There is not one of these blades of grass that, in order to make it curve and hold the curve, has not been pressed on countless times by the bird's breast, its heart."
... Although Bachelard writes about the naive wonder we feel when discovering a nest, I disagree when he suggests that a living, useful nest is valid to our set of images and metaphors associated with nests but that the empty, abandoned nest is nothing. ... The delicate structure; the natural, dulled colour of the materials; the shaping; the accidental debris, the memory only, of seasonal usefulness; the architecture, the shaping of the space but not the space itself in Bachelard's philosophical terms -- the beauty that literally takes my breath away sometimes -- have nothing to do with images of home, warmth, security, refuge ...'
-- Gay Bilson,
Plenty: Digressions on food