The man at our local pet shop could do this with a flick of the wrist, but sadly the shop is now shut.
It's to do with having the confidence and skill to invert them and press the vent open.
I'm glad I'm not a rabbit.
You do not like rabbit stew, ummm? Are you sure you cooked it right then? It normally tastes lovely and do not normally know anyone who does not like it.