Welcome to the Cremer Group

Social immunity in ants

Social insect colonies are protected against disease by cooperative disease defences of their colony members, providing social immunity to the colony. We use ants as a model system to understand the emergence, mechanisms and fitness effects of social immunity.

The colonies of ants and other social insects are built up by distinct castes. The reproductive caste ­– the queens and the males – produce new offspring, whilst the sterile worker caste performs all other tasks of colony maintenance. This clear separation into a reproductive germline and a sterile soma has shaped the evolution of a social immune system that acts in addition to the individual immunity of colony members to protect particularly the reproductive colony members from disease. Social immunity measures range from collective nest hygiene, sophisticated sanitary care of pathogen-contaminated individuals to prevent their infection to effective treatment of infections and modulation of the interaction network to limit transmission.

We study the behavioural, chemical and immunological mechanisms of individual and social immunity in ants, and how they affect epidemiology in the colony and ultimately colony fitness.


PhD student – DEADLINE for application 08.01.2020

We seek for a highly motivated student to join our team working on the social immunity in ant colonies. The PhD thesis will be integrated in our ERC project ( to elucidate how ant colonies as a whole reach disease defence by the cooperative actions of its members. In particularly, we study the behavioural interaction of the individuals, their chemical communication and hygiene measures, as well as their individual immune responses.

If you are interested, please send an email with your CV and motivation letter to Sylvia Cremer, IST Austria:


Please note that PhD students are accepted to the general IST Austria Graduate school and are affiliated to a research group after a training period (rotations in research groups and coursework). All applications hence need to be formally submitted to the IST Austria Graduate School with a deadline of January 8th, 2020 (

Recent publication


Social network plasticity decreases disease transmission in a eusocial insect

Animal social networks are shaped by multiple selection pressures, including the need to ensure efficient communication and functioning while simultaneously limiting disease transmission. Social animals could potentially further reduce epidemic risk by altering their social networks in the presence of pathogens, yet there is currently no evidence for such pathogen-triggered responses.


Sylvia Cremer
Anna V. Grasse