Conditions Affecting Social Space in Drosophila melanogaster.

The social space assay described here can be used to quantify social interactions of Drosophila melanogaster - or other small insects - in a straightforward manner. As we previously demonstrated (1), in a two-dimensional chamber, we first force the flies to form a tight group, subsequently allowing them to take their preferred distance from each other. After the flies have settled, we measure the distance to the closest neighbor (or social space), processing a static picture with free online software (ImageJ).