One of my Nelson's does the same with its pinky rats. He's never quite understood the concept of constricting it, like my Albino does, so he just pins the pinkies to the corner of the tub until the pressure eventually kills it. It's ridiculous.I'm just happy when he actually does decide to kill them before swallowing though. The majority of the time he'll swallow them live. Unfortunately, the breeder I get them from only sells live pinkies, but luckily they're only a day or two old so they can't do any damage.