Abstract: Following up on previous studies on visual perception of Myrmica sabuleti, I intended to specify this ant species' sensitivity to light intensity. I therefore assessed the lowest light intensity necessary to induce a conditioned response to a visual cue in workers maintained during ten days under a given light intensity and then in the same workers maintained during one day under another light intensity. The visual threshold the ants acquired after a ten day-period under one light intensity appeared to be an exponential function of that light intensity's square root. After an additional one day-period under another light intensity, the ants acquired another visual threshold yet differing from the one presented after the ten day-period under that corresponding light intensity. Therefore, M. sabuleti workers adapt themselves to changes in light intensity initially rather rapidly, and then more slowly over the course of time.