Hi, I am wondering if anyone can confirm that I have the right model. I have three groups of animals. At the start of the experiment Group 1 received treatment 1, Group 2 received treatment 2 and Group 3 is a control group.  Each animal has a specific ID and is allowed to hibernate (I might as well say, these animals are bats). Whenever the animals wake up for a short period (usually around 1-2 hours), their behaviour is monitored until they go back into hibernation. The proportion of time they spend expressing 10 specific behaviours is recorded. This continues until the end of the experiment. We also note the number of days left until the end of the experiment for each arousal and the histological condition of the wing (category 0-5). Every time a bat arouses, we take a measurement so it is like repeated measures on the individual bats but not all bats have the same number of arousals (between 3 and 7 arousals per bat). We want to know if there is a difference among the groups for each behavior. ‘Group’ is the independent variable ‘Behaviour x’ is the response variable ‘ID’ is a random effect with repeated measures ‘Days to End’ is a random effect. We would like to include it as a covariate or fixed effect but it does not seem to be correlated with any of the behaviour variables so I am not sure if it should be included at all. I am not sure if ‘Wing Histology’should be included in the model at all as it is dependent on ‘Group’ and the original treatment given to bats and also likely drives some of the behaviours we see. The model I have so far is: proc glimmix; class group id histopath daystoend; model behavior1 = group daystoend group*daystoend/ dist=beta; random _residual_ / subject=id; lsmeans group / diff cl; run; Have I specified the repeated measure correctly? Should ‘daystodeath’ be included as a random variable as well and if so, how would I do this? Any suggestions would be immensely appreciated. Thank you. ... View more