Vision

Ants have highly developed sensory organs for detecting chemicals and do not have well developed visual acuity. This is also the case for many other insects as well. Yet vision can be important for workers finding and capturing prey, helping workers find and recognize landmarks that can be used for navigating their way while they forage, for virgin females to find males and located a suitable nesting site, and for males to find mates. While in general many ant species do not have well-developed eyes and vision, there are many that possess relatively well developed eyes. Below are some select studies that focus on ant eyes and how vision can be important for ants.

A recent study by Aksoy and Camlitepe (2018) reviewed one aspect of what is known about vision: (abstract) Ants constitute one of the most intriguing animal groups with their advanced social lives, different life histories and sensory modalities, one of which is vision. Chemosensation dominates all other modalities in the accomplishment of different vital tasks, but vision, varying from total blindness in some species to a relatively well-developed vision providing ants the basis for visually-guided behaviors, is also of importance. Although studies on ant vision mainly focused on recognition of and guidance by landmark cues in artificial and/or natural conditions, spectral sensitivities of their compound eyes and ocelli were also disclosed, but to a lesser extent. In this review, we have tried to present current data on the spectral sensitivities of the different ant species tested so far and the different methodological approaches. The results, as well as the similarities and/or discrepancies of the methodologies applied, were compared. General tendencies in ants’ spectral sensitivities are presented in a comparative manner and the role of opsins and ant ocelli in their spectral sensitivity is discussed in addition to the sensitivity of ants to long wavelengths. Extraocular sensitivity was also shown in some ant species. The advantages and/or disadvantages of a dichromatic and trichromatic color vision system are discussed from an ecological perspective.

Hunt et al. (2018) studied asymmetries in left and right eye ommatidia count of T. albipennis. This work was stimulated by an earlier finding that individuals searching for new nest sites exhibit a leftward turning bias. They found "Fifty-six workers were examined: 45% had more ommatidia in the right eye, 36% more in the left, and 20% an equal number. A tentative connection between relative ommatidia count for each eye and turning behaviour was identified, with a stronger assessment of behavioural lateralization before imaging and a larger sample suggested for further work. There was a clear sexual dimorphism in ommatidia counts between queens and males."

References

• Aksoy, V. and Y. Camlitepe. 2018. Spectral sensitivities of ants - a review. Animal Biology. 68:55-73. doi:10.1163/15707563-17000119
• Hunt, E. R., C. Dornan, A. B. Sendova-Franks, and N. R. Franks. 2018. Asymmetric ommatidia count and behavioural lateralization in the ant Temnothorax albipennis. Scientific Reports. 8:11. doi:10.1038/s41598-018-23652-4