I know that they are suppose to be diurnal but I have found many a Radix out cruising my backyard in the dead of night 1-4am. Their doing what I'm doing. Catching worms. I've even had the opportunity to hand feed a few while I was out. I agree with all the statements about moving slowly. Remember, just because you don't see any doesn't mean they don't see you. Stopping and remaining still, gives you a good opportunity to see their movement. Be patient. They know more about the area than we do. They blend in and we stick out.