Remote Control Brood: The Influence of nest spatial dynamics on ant social behaviour
Sean Gregor McGregor, Sean McGregor , Fazil Emre Uslu , Matthias Ruegg , Selman Sakar , Laurent Keller
University of Lausanne, Switzerland; University of Lausanne, Switzerland ; EPFL ; UNIL; EPFL ; EPFL ; University of Lausanne, Switzerland
The environment around us plays an important role in shaping and influencing our behaviour. In social insect colonies, the nest environment is a product of their own design. A complex architecture housing several hundred, to many millions of related individuals in a highly structured social network. This network consists of several distinct groups, and individuals, if displaced, return to previously occupied locations, tightly linking the social network to spatial positioning. At the heart of each of these organised, jostling colonies, are the brood. Given the great lengths that social insects invest in their nest design and the spatial fidelity that individuals present, it stands to reason that the location of brood may be critical in regulating behaviour, and has previously been implicated as a potential origin of division of labour. Recent work finds that the relative position of the brood pile may regulate the dynamics of the ant social network and in turn, social behaviour. We aim to test this prediction by remotely controlling the position of the brood pile in colonies of Camponotus fellah and capturing their behavioural response. Controlling brood pile position in a species that designs its own artificial habitat is challenging. Fortunately, ants are highly thermosensitive, and have evolved mechanisms to regulate thermal fluctuations, the most general being the relocation of brood along temperature gradients. Relying on this characteristic, we have invented a device that subtly alters fine thermal gradients under the entire nest surface floor, stimulating a brood relocation event carried out by the ants themselves. This device is thereby capable of altering the colony spatial structure at will and integrates with pre-existing automated behavioural tracking systems, permitting us to test the prediction that colony level behaviours are driven by this environmental signal.