This is not meant to be funny, But the best time is when it is hungry. You can tell this by when food is offered it will almost instantly start to close up on the food. If It does not do this It may not be hungry or may not like what you are feeding it. I have found when offering food if you move it a little after it has started to close around it they may think it is alive, This is just an assumption though. When food offered is not eaten remove it and try again in a few day's or switch what you are feeding JMO
Bill