I grew up in a house where magpies threw moss down off the roof. I don’t suppose they particularly meant to throw it, they were simply looking for insects in or beneath it and I am sure there were plenty.

As well as hiding creatures such as soil mites (which birds will eat), moss provides great nesting material for birds: where dunnocks line their nests with moss, many garden birds such as chaffinches, goldfinches, blackbirds and robins actually build the nest with woven moss. Often it will be interlaced with twigs or feathers, but for some it is nothing but moss which makes for a soft, warm construction.

Some of the moss off our roof landed in the gutter and lay there gathering water. But what provides a more fertile starting point for some lucky seed than a clump of soggy moss? There was a rowan seedling up there once, until Dad cleaned the gutter! Where moss or similar detritus lands in the fork of a tree - and doesn’t get cleaned out – seedlings can grow to quite a size. The moss holds water very well too so can allow the germinating plants to survive long dry spells.

Although the received wisdom is that moss on the roof is damaging, it generally isn’t unless it’s excessive. On the other hand, the benefits to wildlife in terms of food, moisture and nesting material are many. (Of course the very best would be a true green roof, but that’s just not possible on your tiles!)

It wasn’t only the roof of our house that provided fertile feeding ground: blue tits regularly worked the lead-lighted windows – clinging to the lead and picking out mites and insects, and probably algae and moss fragments too. Even if you have more modern windows, your rendering or the rough edges of stonework on your house can harbour insects and tiny amounts of moss or plant growth that’s of huge benefit to wildlife without being detrimental to your house. If you’re really lucky you might notice a treecreeper working the masonry for insects (pied wagtails seem to love the corners of my window reveals), or a wren in the ivy.

So when you’re doing a bit of property maintenance and you remember that advert for someone who’ll clear the moss off your roof, consider for a moment whether it’s really a problem yet, or whether you can leave it a while and let the wildlife benefit.