Over 2cms I'd say, maybe 3. Never got close enough to check. Dark colour. First saw them probably 30 years ago when they were living in front garden. I got rid of them with some old sump oil. I remember how one of their soldiers came after me for maybe 20 metres across the lawn, changing direction every time I did. Eventually I stomped him. They survived and migrated maybe 300 metres down across a creek. I've watched them over the years build up their big nest but they don't bother me where they are. They don't seem to come out in numbers even when I accidentally bump them with the ride on.
