The weekend on or nearest to St Valentine's Day marks a seasonal ritual for us: the annual pre-spring-cleaning of our blue tit nest-box.
We hung our first box in the Scots pine in the corner of our garden in 2002. Since then, we've had a 100% success-rate in terms of having birds nest in it. I'm guessing, as with human habitations, it all boils down to location, location, location: the next-box is located fairly high up in the tree, in a quiet corner of the garden, with its hole pointing north-east, away from the sun and prevailing wind (and, conveniently for us, towards the house).
It's generally seen as good practice to clean out your nest-box at this time of year, shortly before the blue tits begin searching in earnest for nest-sites for the coming season. And the boxes certainly do seem to need cleaning. There are always scores of pupae of some description—bird lice, I'm guessing—hiding in the nooks and crannies. I've never been able to work out whether they're still alive—I suspect not—but they would certainly put me off nesting there, if I were an upwardly mobile, ambitious young blue tit. So, out come grandad's old stepladders, I remove the nest-box from the tree, chuck last year's delicate nest on to the compost heap, scrub the box with a wire brush, and disinfect it with boiling water. For good measure, I then drill new drainage holes in the bottom of the box (they always fill up during the year), before re-hanging it in the same place in the Scots pine.
Based on our previous-success rate, I'm quietly confident that we'll have new potential occupants checking out our nest-box shortly. But I really shouldn't count my blue tits before they're fledged.