Mucus galore - and yet my snail never blows its nose.

Everyone recognises the gorgeous, silvery path leading to their precious lettuces, in poetic rhyming language a snail trail. Some call it slime but this suggests that it isn't useful and that it is waste matter. 

He is too polite to leave a long trail on a pristine background.

As the snail slides forwards, glands in the foot secrete mucus which has several vital roles.

Navigation and communication. The sparkling, alluring trail leaves signals for other snails and itself. I have mentioned elsewhere that its heart rate rises if it finds a stranger's footprint. Chemical signals tell it where food, shelter and mating opportunities are to be found. A well-fed snail is constantly on the look out for a spot of rumpty-tumpty (more of this in a later post). It can use its own trail to revisit a worthwhile location..

Saving moisture. Snails need to be damp and, without this trail, their bodies would dehydrate dangerously as they slither over dry ground.

Stickiness for climbing. When the snail is on horizontal ground, its thinner, slippery mucus reduces friction but, on vertical surfaces, it provides strong adhesion. My snails are avid mountaineers which is why the best is called Sir Edmund.

Protection and lubrication. If the snail has to traverse rough ground or sharp rocks, the mucus protects its soft foot. 

So - that is why, even if you offer your snails a box of tissues and one looks interested, he will not, in the end, blow his nose.