Icy-breakers ahoy for the garden birdbath

SIR – Maurice West (Letters, December 16) asks how to prevent his birdbath from freezing over.

When an overnight frost is forecast, I empty my birdbath at dusk – or earlier if necessary – and refill it the next morning. If it starts to refreeze I disperse the ice with a trowel before it has time to harden. Judith Cairns

Helmdon, Northamptonshire SIR – My late grandfather would add a drop or two of whisky to the water. This did seem to work – the only problem being that those birds which had imbibed were often unable to take off for a while.

Perhaps this particular method is not recommended unless one’s garden is a cat-free zone. George Baker

Stockton-on-tees, Co Durham