Associative learning in ants: conditioning of the maxilla-labium extension response in Camponotus aethiops

J Insect Physiol. 2010 Jan;56(1):88-92. doi: 10.1016/j.jinsphys.2009.09.007.


Associative learning has been studied in many vertebrates and invertebrates. In social insects, the proboscis extension response conditioning of honey bees has been widely used for several decades. However, a similar paradigm has not been developed for ants, which are advanced social insects showing different morphological castes and a plethora of life histories. Here we present a novel conditioning protocol using Camponotus aethiops. When the antennae of a harnessed ant are stimulated with sucrose solution, the ant extends its maxilla-labium to absorb the sucrose. We term this the "maxilla-labium extension response" (MaLER). MaLER could be conditioned by forward pairing an odour (conditioned stimulus) with sucrose (unconditioned stimulus) in the course of six conditioning trials (absolute conditioning). In non-rewarded tests following conditioning, ants gave significantly higher specific responses to the conditioned stimulus than to a novel odour. When trained for differential conditioning, ants discriminated between the odour forward-paired with sucrose and an odour forward-paired with quinine (a putative aversive stimulus). In both absolute and differential conditioning, memory lasted for at least 1h. MaLER conditioning allows full control of the stimulation sequence, inter-stimulus and inter-trial intervals and satiety, which is crucial for any further study on associative learning in ants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Ants*
  • Association Learning*
  • Conditioning, Psychological*
  • Odorants
  • Quinine
  • Sucrose


  • Sucrose
  • Quinine