I have been thinking about this. Like bunnylady, I think it is highly improbable that the doe could or would kill and eat the kits this late in the game and do so without leaving a trace. While the snake can get in through a very small opening, once he swallows his prey there is a large bulge in his middle and it is unlikely he could get back out until his meal is digested and that takes time. Something is getting them, that's for sure.