Small but mighty! Introducing the wood ant

Did you know that a ferocious predator lives on many of our heaths and forests? This creature can lift over 100 times its body weight and squirt formic acid 12 times its body length! If humans could run the equivalent speed of this animal, we would be able to run as fast as a thoroughbred horse! Sounds terrifying but this creature is only around 1cm long – it is a wood ant (Formica species).

It is so easy to forget how incredible our wildlife is. I am lucky enough to see and hear a variety of wildlife on a daily basis and I’m ashamed to admit that I can get complacent about it. However, whenever I have the privilege of showing someone else what lives in our countryside, it reignites that awe and wonder.

The wood ant is a prime example of this. Whilst walking for pleasure with a friend on Bramshill Plantation in Hampshire we spotted an enormous mound that was teeming with activity. They were awestruck! It was a wood ant nest. The biggest, most mature of these nests can reach up to two metres tall and what you can see above ground isn’t the whole structure – there’s usually the same amount or more underground. Wood ant nests are an architectural feat. Internally there are tunnels and chambers containing the queen and her brood, food stores and even a graveyard. Tunnel entrances can be opened or closed to maintain the optimal temperature for the nest’s inhabitants. Take a close look at the thatched surface of a nest and you will notice that it is made up of pine needles, twigs, moss and heathers. What you won’t realise is that the thatch is laid in such a way that it intercepts the sun’s rays at right angles, acting like a solar panel. Bit of rain? No problem, the thatch is laid to act like an umbrella, directing water away from the nest, keeping the inside nice and dry! If the nest isn’t warming up in the way they would like, ants will sunbathe on the top of the nest to absorb heat from the sun and then return to the brood chamber to release the heat.

Even if you don’t notice a nest you will likely spot wood ants going about their business as a healthy forest will contain an incredible 500 wood ants per square metre. They can be seen in trails along the woodland floor, across paths or making their way up trees.

Most of their diet, approximately 90%, comes from honeydew produced by aphids. Aphids feed on tree sap which is high in sugars and as they feed, they excrete excess sugars as honeydew. A tasty source of energy for a wood ant, they will “milk” the aphids of their honeydew and return to the nest to regurgitate it for the queen and other workers.

Keep your eye out when you are out walking for these little creatures and appreciate how absolutely amazing they are!

Hannah

Thames Basin Heaths Partnership