Workers of the acrobat ant (Crematogaster scutellaris) feeding upon the sugary secretion of aphids that sucks the petiole of a holm-oak acorn. The nests of the acrobat ant are located into alive or death woods of several tree species. When the acrobat ant feels threatened or in case of knocking at their trunk, they will immediately exit from the trunk and they'll raise the abdomen. A pheromon for alarm is delivered from the tip of the abdomen. The pheromon breaks out a general alarm in the acrobat ant nest. Any foreigner soon is surrounded by an army of aggresive ants that bite it. The ants are large group of hymenoptera families with outstanding ecological functions as organisers of the soil ans disseminators of seeds.

[photo Florenci Vallès]