Skin that stops snakes sizzling

QUESTION Do snakes suffer from sunburn?

A SNAKE’S scales are particularly effective at blocking UV light, which can cause sunburn.

They are made of keratin — a protein that is the main constituent of hair, feathers, hoofs, claws and horns — and also contain waxes to prevent water loss.

The scales’ structure is akin to small, flat roof tiles. Despite their apparently smooth surface, each has many concave holes into which light is scattered, helping to prevent sunburn.

Snakes will lie in the sun for long periods without harm. This is important for their survival: as cold-blooded creatures, snakes must bask to raise their body temperature. The sun also maintains vitamin and mineral levels.

Animals without scales, feathers or fur have various other methods of protecting themselves from the burning. Pigs and rhinos wallow in mud, as do elephants, which toss soil, dirt and sand on their backs and create a protective shadow for their young. Hippos secrete an oily, pinkishred liquid around their ears and faces — the only parts above the water’s surface when they wallow — that absorbs ultraviolet light.

Ian Ross, Edinburgh.

QUESTION What is the origin of the term ‘blithering’?

I NOTED that the explanation for this term came from a reader who grew up in Cork.

I attended Hanley Castle grammar school, Worcestershire, in the Fifties and we had an Irish chemistry teacher from Cork.

His scale of insults started with idiot, then blethering idiot, then blockhead and block- headed blethering idiot. We gave wrong answers just to be insulted.

John Colbert, Walsall, W. Mids.