Ant antennae provide chemical ID

Ant antennae don’t just receive chemical signals — they send signals, too.

Colonies of ants communicate through chemical cues produced all over their bodies. Studies have shown that ants use their antennae to identify their own nest mates and potential invaders. But antennae also produce the key compounds that ants use to tell friend from foe, researchers in Australia report in the March 30 Proceedings of the Royal Society B.

Antennae from Australian meat ants (Iridomyrmex purpureus) contain a different chemical cocktail than what is found on ants’ heads, legs or abdomens, the team found. When a worker ant’s antennae were removed or dipped in a solution that washed away signaling chemicals, ants from a different colony couldn’t identify the intruder. The unaltered ants brushed the invader with their own antennae, and then acted as though the impostor was one of their own.