Michael Viney responds to queries and observations on nature.
Over the years I have occasionally received bottles of wine in well-crafted wooden boxes with sliding lids. Are these of suitable size for use as bird/bat boxes? If so, what size hole and position on box; in which direction should they be oriented; and at what height on the tree/wall?
Malcolm Mitchell, Kilternan, Co Dublin
Yes, they can be used upright as bird nesting boxes with drainage holes in the floor. The entrance hole should be at the top of the front or side, and 29mm in diameter. Boxes should be placed at a height of about 1.8 metres, protected from prevailing cold winds and shaded from hot sun, in the arc between northeast and southeast. The birds should be given a clear flight path with a convenient staging post about two metres away.
What does a spider find to eat living as it does in my shower room which has tiled walls and floor. There is a potted plant on the window sill.
Margaret Thompson, Shankill, Co Dublin
The female house spider can exist for several months in houses without either food or drink. And then she can get lucky and find a passing insect.