Awhile back (I guess in the very old times before the big neurostars DB vanishing since I cannot find it now) I was asking about a toolbox to assist tracking animals in behavioral experiments. A student let me know about https://github.com/AlexEMG/DeepLabCut which looks really powerful and well documented.
Excerpt from the README:
DeepLabCut is a toolbox for markerless pose estimation of animals performing various tasks. Originally, we demonstrated the capabilities for trail tracking, reaching in mice and various Drosophila behaviors during egg-laying (see Mathis et al. for details). There is, however, nothing specific that makes the toolbox only applicable to these tasks and/or species. The toolbox has also already been successfully applied (by us and others) to rats, humans, various fish species, bacteria, leeches, various robots, cheetahs, mouse whiskers and race horses. This work utilizes the feature detectors (ResNets + readout layers) of one of the state-of-the-art algorithms for human pose estimation by Insafutdinov et al., called DeeperCut, which inspired the name for our toolbox (see references below).