What happens to daddy's when they die?

This morning over breakfast, one of my 3.5 year olds was chattering away at me. Then he posed a question, which at first I didn't quite understand.

Son: "What do they do with daddy's when they die?"

Me: "What do they do with them? Or where do the daddy's go?"

Son: "What do they do with them?"

Me: "Uhh, well, it all depends on..."

Son: "Do they put them in a case, like mommies?"

Me: Where on earth is he getting this stuff? "A.. case?"

Son: "They wrap up the mommies and put them in a case."

Me: (laughing) "Ohhh, you mean mummies?"