Ahem.
(This one only works if you were a parent in Australia in the late 70s early 80s.)
Q: Where do baby elves come from?
A: The Baby Elf Centre. (okay - we had Baby Health Centres. Work it out...)
For the rest of you:
Q: Where do baby apes sleep?
A: Apri-cots.
ETA: And my personal favourite which for maximum lolz has to be delivered by a very serious four-year-old
Q: Why did the little chicken cross the road softly?
A: Because it was just a baby chick and it couldn't walk, hardly.
ETA 2: (Oh, look. Find a four-year-old. It works.)