Curling Ant

I have never seen this ant about during daytime. They appear to be solitary or to have sparse density and tend to be found on gum trees with many crevices in the bark. The moment they sense anything they hurl themselves into the nearest niche and curl up and refuse to move. They do not seem to hold the position as an attempt to bring a stinger into play.

Images two and three have been heavily modified so the parts of the nat can be more easily seen to assist identification