Ant fighting

Fighting an enemy until the enemy dies

Some kinds of ants are quite aggressive in protecting their nest or food resouces. The enemy sometimes may be an ant of the same species and sometimes of a different ant species. The fight is continued until the enemy's body is dismembered or it dies.

Confirming smell by the antennae

Even ants of the same species sometimes show aggressive behavior if they come from a different nest. When ants of the same species meet outside the nest, they smell each other using their antennae. This allows them to distinguish their fellow ants from those belonging to a different nest.
Greeting of Camponotus obscuripes
Confirming the origin of another ant using the antenna

Fight by releasing a poisonous fluid

During a fight, a poisonous fluid called formic acid is sprayed from the edge of the gaster. Some Crematogaster ants spray formic acid from above by curving the abdomen upwards behind the body. The Formica ant sprays the juice from below by curving the abdomen upwards in front of the body.

Fighting by Crematogaster matsumurai Droplets of formic acid can be seen at the tip of the abdomen.