"Who likes to sleep and eat?"
Translation:Кто любит спать и есть?
in a nutshell: кушать is colloquial.
есть is the neutral translation of "to eat", кушать is mainly used in conversations among family members. My russian teacher (from Russia) told me, it would be kinda strange and funny, if someone would say кушать in a restaurant to a waiter.
Maybe кушать is like the german word "mampfen", which might mean "to munch" in English (not a native English speaker, sorry).