Ants are diverse and ubiquitous, and the ability of certain species to deliver a painful defensive sting is something that is familiar to many of us. Over the last 5 years, I have explored the chemistry and pharmacology of ant venoms. I have revealed that most stinging ants venoms are relatively simple and composed largely of peptide toxins; 1 that these peptide toxins are responsible for the painful effects of ant stings; and that multiple classes of pain-causing peptides exist. These include (i) structurally diverse pore-forming amphipathic peptides related to melittin, which cause “short, sharp pain”; (ii) a new class of unusual lipophilic peptide toxins that potently modulate vertebrate neuronal voltage-gated sodium channels to cause longer-lasting, intense pain;(2 and unpublished) and (iii) EGF-like peptide toxins which mimic vertebrate EGF-like hormones to cause long-lasting hypersensitivity.3
The identification and characterisation of new pain-causing toxins from ant venoms has provided new knowledge about their chemical defence; highlighted the role of certain ion channels and receptors in mammalian pain signalling; and provided a suite of new peptide tools to study these.