We're bunny sitting just now or well looking after a pair of buns in their own house. They live in an indoor cage in a playhouse, the cage is 2 storey but tiny they certainly cannot run around it.
I let then put today first good day for a while and they didn't want to go out for a run kept trying to get back in the cage. 
I see this a lot another friend has a line rabbit in a tiny cramped hutch never allowed out
stick at the bottom of the garden.
I've had bunnies before and they had an outdoor run and were out most days even in winter and they had a hutch in a shed and the run of the shed floor.
I was thinking of getting bunnies or piggies for the DC but have decided to get a dog instead so can't get bunnies now (dog will be a large sight hound).
I guess I just get so sad about bunnies stuck in a cage that can't run about 