I was thinking the other day (when my Redfoot decided to eat one of the plants in its enclosure, the only time it ever has eaten one growing in there, and it happened to be not toxic for her and the plant also happened to be from where she is native to), do tortoises know what they can and can't eat? I know you shouldn't throw food at them that is obviously not good for them, but if you have them around live plants that aren't edible, will they know not to consume them? They've survived forever in the wild without humans picking out what they can eat. Don't most animals either naturally know not to consume something poisonous or spit it out if they bite into it and can tell its not quite right? Maybe this even depends on the species?