NATURE NOTES
There are armies out there – vast, uncountable armies – building and defending kingdoms with a frenetic urgency that makes you thank the stars that those six-legged soldiers are actually really tiny. In the pine forests, at the foot of the mountains, are one of Nature’s true spectacles – wood ants.
I have a recurring nightmare. I’m having a midday nap in a pine forest. The next thing I know I’m being squirted with acid from the anal glands of my assailants. My skin starts to dissolve as I’m carried away by hundreds of would-be assassins. I’m then cut up and chewed up, before being sicked up in liquid form, into the waiting mouths of my captors’ larvae. Luckily for me, I’m not a caterpillar, because that’s exactly what happens to them if they’re unlucky enough to be in the way of a wood ant worker patrol, on the daily hunt for the huge amount of food a colony needs.
Wood ants can also squirt acid (formic) at any would-be predators. Find a wood ant mound in the summer and its surface will be heaving with busy ants. If you’re feeling brave, place your hand gently onto the nest. It’ll be immediately covered in ants. If you look closely you’ll be able to see them curving their abdomens (back part of the body – insects have a head, thorax and abdomen) towards your hand, and you may even see the squirt of acid. Shake the pesky critters off, then smell your hand and you’ll recognise the scent of vinegar (that’s formic acid). Luckily this does us no real harm.
There are four or five species of wood ant in the UK. The ones I’m particularly thinking about live in the Caledonian pine forests of mountain regions of Scotland like the Cairngorms. In a colony of wood ants there can be as many as 300,000 worker ants, all are female and about 6mm long, with a dark brown head and abdomen, with the middle part of the body (thorax) being ginger in colour. Males emerge for only a short period of time to mate and then die shortly afterwards. And then there’s the queen, or should I say queens, as a colony can have more than one. These are about 10mm long and when seen are normally in the winged phase of their existence, a life that can be as long as 15 years, compared to the one or two months for workers.
Once mated, the queen will lay thousands of eggs. These will be shifted around the nest by the workers so they’
