Good day guys I need to conduct the behavioral tests on rats. I need some free program for social behavior; the program should be able to track two rats simultaneously, their movement trajectories and time spent by these animals when they are close or far to each other (and to analyse the results statistically if possible, however this is additional requirements. At least the program should be able to track the rats). Which program would you advise me? The Dutch company “Noldus” offers us good programs, but they are not free of charge. I have heard that some such programs are developed by the National Institutes of Health, but I could not find anything at their web-site. Can you help me?