have a ball

RSPB images/Chris Gomersall

The RSPB is urging gardeners to put ping-pong balls or corks in birdbaths during cold weather to prevent them freezing over

The motion of balls or corks in the wind keeps the water moving, making it less likely to freeze.

Garden birds such as this chaffinch depend on birdbaths for drinking water and feather washing. Bathing and preening are essential to keep their feathers in good condition, which in turn helps them find food and evade predators.