How do moles smell underwater?

Blowing Bubbles

I was pleased to see the mention of the star-nosed mole in Nick Richardson’s review of Ned Beauman’s latest novel (LRB, 17 July). Richardson informs us that this marvellous creature ‘can smell underwater’. True, but not thanks to the ‘nose’ that gives it its name. The 22 fleshy appendages that protrude from the mole’s face are not an olfactory organ at all, but a skin surface containing more than 100,000 sensory neurons – it’s the most acute touch organ of any mammal on the planet and about six times more sensitive than the human hand. In order to ‘smell’ underwater – a phenomenon long thought impossible in mammals – the mole exhales air bubbles over objects then reinhales them, allowing odorant molecules in the bubbles to pass over the olfactory receptors.

Sarah Murray

Esher

The link is here, pointer from Hugo Lindgren.