Those hutches don’t seem very big if I’m honest, rabbits need a very big space to live in and to exercise in. Have you thought about putting them in a cage in your house or even letting them free roam? Do you have a litter tray for them with a hay feeder? Rabbits tend to poop while they eat so many people put the hay rack above the letterbox so they can munch and poop at the same time. They can be trained, you can read about it here in the INFO section. Also if they’re sleeping outside there’s a chance a fox or a cat might come up and scare them. Rabbits can die from fright so you need to think about that as well.

Along with what Boo said, it looks like it would be very easy for them or another animal to dig their way through to the bunnies.