When do bunnies go to sleep?

I just bought 2 bunnies. They live outside in a pen. I noticed they don t go into their hutch when it is fully dark out. Is this common? I am wondering if they will eventually go in on their own and staying out in the dark is normal or if I should continue to put them in their hutch when it gets dark.

The First Dragon

Rabbits sleep, I understand, about 5 minutes per day, and you may never see it. They spend a good amount of time dozing - resting with their eyes open - and from this they get a lot of the benefits of sleep. These are domesticated rabbits, protected from predators, and so they may not care whether they are in a hidden place at night. If they get cold they will no doubt go indoors. Their eyes adapt well to the dark, so they can do this.