Tracking the positions of two mice during social interaction.

<p>(<b>A</b>) The tracking software is able to locate the center of masses of both mice while at different positions in the cage. Representative images of the tracker are shown, showing various social interactions between male-female pairs in the top panels and female-female pairs in the bottom panels. (<b>B</b>) The fraction of frames of a video during which the male and female mouse are within a certain number of mouse widths away from each other. The dark solid line represents the median fraction of frames the mice were within a certain distance and the shaded boundaries represent the upper and lower quartile across the individual mouse pairs for that day. Day 15 (interaction with a novel female) is shown in dark blue, day 28 (interaction with a female for the seventh day in a row) in cyan, and Day 29 (interaction with another novel female) in olive. (<b>C</b>) The fraction of frames of a video during which the two female mice are within a certain number of mouse widths away from each other. Day 0 is shown in dark blue, day 7 in cyan, day 14 in pale green, day 21 in olive, and day 28 in orange. (<b>D</b>) The fraction of frames during which the male-female mice are within two mouse widths (approximately equal to one mouse length). Each point in the scatter plot represents the value for one video (one mouse interaction at one time point). (<b>E</b>) The fraction of frames during which the female-female mice are within two mouse widths.