Can you mix rabbit litters?

Question
This happen many years ago when I was a kid.  We had some rabbits that we kept up on our hayloft of our barn.  One of the mothers had a litter of rabbits.  Shortly after that we found a couple of small wild rabbits that had lost their mother.  The wild rabbits where quite a big bigger than than other baby rabbits.  My cousin and I thought that we would put the wild rabbits in with the mother and her litter and we did so.  Those two little wild rabbits worked their way down into the mix and the next thing we knew they were gone.  The mother and her litter were in an old metal bucket with some straw in it.  We took all the rabbits out and the straw and they were just gone.  No blood or anything.  We weren't trying to hurt these rabbits, but from experience apparently you can't mix litters.  Did the mother rabbit kill these other rabbits or what?  I can't see that the little rabbits were big enough to harm these bigger rabbits.  It's bothered me ever since.  It was the greatest magic trick I have ever seen, but no one ever pulled the missing rabbits from a hat.  That was the last we ever saw of them.  Is this something that normally happens if you try and mix rabbit litters?

Answer
Dear Shawn,

You can sometimes put rabbits from one litter into another, but it's wise to somehow mess with mama's sense of smell (some people say putting a tiny dab of vanilla on her nose will interfere with her sense of smell and keep her from detecting the newcomers until they smell enough like her own babies to not trigger a violent reaction.

This is a sad outcome, but the mama rabbit may well have killed and ingested the wild baby rabbits.  Worse still, the wild babies were probably *not* orphans.  Wild rabbits do not tend their litters, so as to avoid attracting predators.  So they should always be left strictly alone so mama will be able to find and feed them at dawn and dusk.

I wish I had a happier explanation, but that's possibly what happened.  

Dana