We had a long night of multiple "pup rescues", i.e., rescuing pups who escaped the whelping pool and subsequently became very lonely for their litter mates. So, as of yesterday morning, the pups are out of the whelping pool and into a small version of the puppy pen. At first, the pups were a little unsure of the new arrangement, but after an hour or so, they figured out their new spaces for playing, sleeping, and toileting. It's amazing to watch such young babies toddle to the pooch pads to toilet. In a day or two I'll introduce the litter box and hopefully they will take to that as well as they have to the new pen.