Just look at the size of this wood ants nest - my friend is nearly hidden by it! I gather that these large ones can contain as many as 300,000 ants and can be several years old. To them run trails up to 30 metres long along which come a constant stream of worker ants carrying food and nest materials. It is fascinating to watch the ants carrying huge and heavy objects, sometimes much bigger than themselves.
There is one downside though, don't stand on the trail or you will have them running up your leg. And, boy, can those guys bite! They also can spray venom from their abdomens. My worst experiences tend to happen when I'm looking for mushrooms. I've noticed the best mushrooms often grow on an ant trail and my greed sometimes gets the better of my good sense. So if you see a strange British woman hopping around in a Czech forest flapping at her legs you will know it's me.